For those curious about how this race is going to go,
Politics PA is one of the more interesting sites. Currently, there's a little press release war going on from the PA GOP at Bobby Casey.
I can't find the original archived post, but the gist of it was that a few weeks ago, the PA GOP sent out a press release saying that Casey had a meeting with Schumer and company agreeing to lay off abortion issues in exchange for the Senatorial run. Casey sent a response flatly denying it (the relevant quote is in the releases). Since then, the PA GOP has been harping every opportunity they can to paint Casey as a flip-flopper (their term) on abortion - what's interesting is that they're relying primarily on their previous press releases, or quotes from the American Spectator that quote their press releases. Well that and saying that Dean's fundraiser for Casey tars both of them by association.
Here's the URLs:
http://politicspa.com/Press_Releases/040405PAGOP.htm
http://politicspa.com/Press_Releases/033105pagop.htm
http://politicspa.com/Press_Releases/031505pagop.htm
Frankly, it's not like it matters this early in the race, but it's probably a taste of strategy to come. The 3/15 release is the only one that generally addresses policy.