I think it needs alot of improments.
-It only relies on Signatures
-No Behavior Engine - a.k.a NO zero day/hour threat protection
-Automatic removal upon found infections
-Should'nt a AV be: Install and Forget! while MSE has: Install and remember forever!
Good things:
-It detects most of the ugly stuff, but still...
-Its free
-Its good for Windows Basic Protection
Still... I like Avast! Free better - But MSE is new too.