From Stats, Inc.:
Again, I don't think Lopez's return is quite as important as it would appear to be name v. name compared to Fasano, but Lopez's return is going to be nice. Fasano, if he keeps his current pace, is a great guy to have as a backup, but obviously you'd rather have Javy in the lineup most days. When Javy is back, we'll have a pretty fair catching tandem, maybe the best one the O's have had since Hoiles/Webster.
What Javy adds is a bat more pitchers are likely to try to avoid. Fasano does have something of a minor league track record power-wise (.494 slugging and 138 career minor league homers), but I think it'd be fair to say, as much as I love Sal, that he's a fastball-or-nothing hitter. He hits mistakes. And pitchers aren't afraid of him, so he gets mistakes to hit.
Javy's had some trouble coming back from this injury, as the hand swelled up when he was first trying to make it back recently, and I'm worried how much it's going to affect his hitting. A bad hand injury (and everyone who's seen it has said it's pretty bad) could terrorize his swing. I'm also worried it could affect his ability to catch, but we'll see how that plays out. Hope for the best, because if it plagues him badly it could really screw up our roster.