The iPad 6 probably won't be out until Sep or Oct - if you can wait that long, it might be worth it to see how much better it is than the current iPad Air. From what I've read in the rumor mills (emphasis on "rumor"), it's going to be incremental improvements (bigger viewable area, fingerprint sensor, etc). If you don't think it rates the price premium, you may have an opportunity to get the current Air cheaper if they lower the price along with the new model intro, although I wouldn't count on it.
I'm typing this response on the current Air which I've been using since it was released. If I needed an iPad now, I would purchase the same model again. It's been awesome for personal and business use, especially mated with a Belkin...