if you like carbon bikes, the FELT Z6 (2011 model) has comfy geometry and almost a complete 105 group set. all for about $1500
leaves you with $500 for extras
i was in the same situation a few weeks ago...increased my budget a bit and got a Felt Z5
i also tried a Specialized Allez Elite...great aluminum bike also with 105 group set
plenty of choices, just make sure you ride all of them before making your decision