Robin - I do a combo of Yoga/Pillates and cardio. I don't do weights anymore because I found that with yoga/pillates I get more than enough strength training. I don't think you realize how much strength it takes to do yoga. My schedule is as follows:

Monday - 15 minute ab class/1 hour yoga (he uses a little pillates as well)
Tuesday - 45 minutes cardio
Wednesday - 15 minute abs/1 hour yoga
Thursday - 45 min cardio
Friday - rest
Sat - 45 minutes cardio
Sun - yoga/abs (do tape at home)

If you wanted to still do weights you could incorporate it on a cardio day. I strongly recommend that you don't try to do weights and yoga or yoga and cardio on the same day.