Are you also doing any martial arts right now? Do you have any flexibility/mobility issues that concern you?
This is a touchy question to answer because I happen to think very highly of yoga, but it has been appropriately criticized for its emphasis on lumbar flexibility. The way yoga is taught in many gyms, more as a cardio class or as a stretching class, is not what yoga is really about. So my answer has a lot of "it depends" clauses in it. :p
Here is a link to a thread that introduces an article Eric Cressey wrote called
Yoga This and Pilates That. You can read it on the FitCast.com website (there is a link in the thread), but also please read the discussion in the thread. This discussion might help you decide if yoga is a good choice for you, or if there are other modalities that might suit you better.
Eric Cressey: Yoga This and Pilates That