As I prep for my upcoming GPC, Ive been reading various blogs and listening to David Larkins amazing "Esoteric Order of Roleplayers" (http://esoteric-rp.blogspot.com/), which is a great resource for "seeing" the game in action.

One thing I've noticed though is that the PK's tends not to give much of a damn about most of the major NPC's--Uther, Merlin, etc. In fact, it seems many players take a certain amount of pleasure in finding reasons why their characters don't care for these NPC's. I can see hating on Galahad--I mean, even when I was in my "I'm 12 and want to grow up and be a Catholic Priest" phase I couldn't stand Galahad. Or Lancelot for that matter. (I've always been a Gawain/Percival fan boy). Anyway, anyone have any tips for helping get the players to actually care about some of these characters?

Uther, in particular, strikes me as a very tragic figure; he's the man who should have been the High King, or should have brought about an era of peace and prosperity a generation early, but failed due to his own human vices. The GPC doesn't really give us a lot to work with him, but I want my PK's to be loyal to their King, to care about him, and so when he stumble and falls, it means something.

Here's my idea--Aurelius and Uther were a fearful team. Aurelius had the political cunning and social grace to unite the various lords of Britain under his banner, but couldn't fight worth a damn. Uther took care of that part. Together, they were an unstoppable team--what Uther couldn't conquer, Aurelius could cajole. In many ways, there were the British version of Octavius and Agrippa.

Unfortunately, with Aurelius' death, the balance is undone. Uther is a wonderful soldier and warrior, far more comfortable in the field than in the palace. He talks easily with the common soldiers, but can barely mask his disdain for the great lords of Britain (esp. the members of the collegium, who seem to take a perverse delight in holding their power over him). As such, I want to play up hie "earthiness"--have him walking around with the men before and after the battle, praising the wounded and glorious, sharing stories (often crude and profane), eating the same grub as everyone else. I want the PK's as relatively young and "common" knights to feel that he's one of them.

I also want to play up the idea that he's a SMART commander. If the GPC, he seems to blunder into battle after battle, accomplishing little until St. Albans. This might be accurate as far the Matter tells us, but I want the players to like this guy. I want Mearcred creek to be him snatching victory from the jaws of defeat--maybe by really playing up the whole "Where is Cornwall and the other Dukes" element. When it comes to St. Albans, I don't want him to win by dumb luck, but maybe by cunningly luring the Saxons out into the field --perhaps he sends "deserters" to flee and spread false information, while having his army fake a "fleeing" to get them into grounds of his own choosing?

Basically, when he dies, it should be a devastating loss, not a "oh, so that happened."

As for Merlin, I again want to play up his charisma. I want him to be more than just a font of mystery and suspicion. I want to play up his role as spiritual leader of Britain--pagans (both characters and NPC's) should revere him, and hosting him should be a great honor. I know it's not the most "genre appropriate" text, but I was thinking of stealing from Stephen Lawheads Pendragon Cycle for my take on Merlin.

Finally, I wanted to play up the Questing Beasts role as the embodiment of the unnatural lusts and desires that will eventually destroy Arthur's Kingdom. I;m not sure if I want to tie it to "Love (Family)" in some perverse manner, or just do it through tales and roleplaying.

Any ideas?

I think you are already a good way up the right track.
You could use Prince Madoc as a way towards the King. In my game Madoc was a joyful, but somewhat brazen knight who got into trouble alot and had to be saved by the PK several times.
As for the King himself he was a bit more distant. When he started the war with Cornwall they went along reluctantly. In the end they were with Madoc and tried to save him. One of the PK killed the duke, but would rather he had not.

We are in 499 currently so the loss of the King is all present as they are beset by enemies.

Merlin is aloof and currently several hate hij. So I am thinking on how to prevent a slaughter when he returns.

I agree with what Cornelius said: you have a good idea there. Another couple of suggestions, one a bigger one, the other a specific incident...

1) Make sure that your PKs get some face time with the King. Meeting him, having him be interested in them and their adventures, some praise for heroics well done... Extra Glory from being recognized by the King, perhaps minor 'Christmas Presents' like a fancier set of clothing from the King to his 'special knights'. This might be something you had already in mind, based on your 'earthier' Uther.

2) Rewrite the Syagrius incident slightly. Have the trigger be Syagrius' inability to gather as large an army as he promised rather than pre-planned 'welching' by Madog. Have the spies find the size of the Frankish army, and everyone convinced that it is a high time to get out while getting is good. Have Syagrius more petulant and unreasonable and snooty, perhaps even insulting the PKs. In short, make Syagrius the bad guy here, not Prince Madog & Uther. That way, they come off smelling more like roses, the smart, sensible leaders unwilling to sacrifice their troops on a lost cause, rather than amoral opportunists who do not honor their alliances.

3) Oh, while I remember... The other thing is Uther pretty much neglecting his Kingly duties post-Ygraine. You might wish to spin that into something else, such as sensibly standing aside while the Saxons fight amongst themselves.

In our campaign, Uther is a tyrannical King with lots of pride and a temper. But he is still loads better than the Anarchy that follows. And that is the feeling I want my players to have. A King is better than no King at all. :)

There is no secret here: make your NPC fully rounded characters with strong emotions, goals of their own and a quirk or two, and your players will give a damn. That seems to me to be what you are doing.