That's a really good offer for Colorado. They'd dump Helton's big contract and get a pretty damn good prospect in Markakis. Markakis has superb tools and really seemed to be finding his groove at the plate last year. Since he was a two way player in JUCO (in fact, most liked him as an LHP...in a different system like Colorado, it wouldn't be TOO surprising to see him go back to the mound, but since he's had a couple of years at the plate, that'd make it a bit iffy), he's been a bit slower to develop, but the raw ability is certainly there. While most doubt Markakis will develop big time power, he could be a lesser Helton out there.
This would also open another spot where they could move Garrett Atkins/Jeff Baker/Ian Stewart...
From the O's perspective, it really doesn't make sense. Their farm system is already REALLY thin, especially after Adam Loewen pretty much busted and Wade Townsend went back to school (should've drafted Nelson like some of their officials wanted...I think Angelos made the call on Townsend). The Sosa deal was decent, but if they're going to kill their farm system, they might as well do it for top starting pitching. They need a frontline starter to anchor the staff...not another bat.