Ah - maybe that's why I don't hate every new male character into'd on the show -- I'm the anti-shipper! I don't want any relationships to develop on the show btwn the major characters - and I'll explain why:
Many times when show PTBs decide to 'ship' the characters, they then focus the show on the relationship, and not on the initial intent of the show. Focusing on the relationship and not on the 'idea' makes for really boring television. If they could find a way to put characters together and not have the show stink up the place, I might consider it, but since I'm relatively certain there's not a chance in hell they'd do it right, I'm really hoping they never do. (Then, on SG-1 there's that whole 'chain of command' thing that's all in the way) --
So, do I hate McKay? Nope. Do I love him? Nope. Should he stay? Yeah sure, as long as he's useful, but when they stop coming up w/ reasons for him to be around - ship him off somewhere.
Don't kill him. There have been too many characters killed off this show, we don't need to kill off all the characters we don't like very much.
On a slightly different note, don't keep a character just b/c we love him. It is perfectly acceptable to kill off the good guys - (ie: Kawalski, Martouf) - not a popular decision, but just as valid as killing the bad guys -----