Some good comments here. I use a few open tunings on a regular basis, but it's worth noting that there is a drawback to open tunings, particularly if you use a lot of them. The problem is that they make the fingerboard unfamiliar territory, which makes it difficult to improvise, or really to play anything that hasn't been painstakingly worked out in advance. If you only use a few tunings, you can get past this -- what was unfamiliar becomes more familiar the more you work with it. But the further down this road you travel, the more this can become an issue.

It all depends on how you play, of course. If you tune to an open chord and just run a barre over the strings, then maybe this isn't an issue (as long as you don't want to play minor chords). Or if you are accustomed to playing a very established part as backup to vocals, etc., maybe the unfamiliar terrain doesn't matter so much (people like Joni Mitchell and David Wilcox take this approach, as do a lot of the Hawaiian slack-key guitarists). But if you tend to get a touch of wanderlust as you're playing, it's easy to get in over your head. Good luck.