My one concern at this point, though, is the very limited character selection (you have 4 people to choose from, and that's all). There's no creator, so you can't change anything about your 'player', save for name and clothing colors... which is sad.
I do, however, like the idea of joining any online game and bringing in every detail of your character - weapons, skills, items, experience points, etc, etc, and they continue to grow; so when you finally go back to your own game, everything you did online is still counted, and you can continue right where you left off (with the mission progress being different, or not).
It's probably worth a look, however I have to admit this is probably a 'filler' until some of the better titles come out - ala, Assassin's Creed II, Modern Warfare 2, and (perhaps) Dragon Age: Origins.
Not too sure about the last one there, but I have the other two paid in full and waiting for release.
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