No don't wait.
Well really it depends what you have now and what you can't do because of it!
For me it was the 400D low ISO limit that forced me up to the 60D 3 months ago - LOVING IT - especially the dual roller dials - way better than the one control dial on the 400D.
Great battery life, amazing ISO performance, and with almost twice the Mpixels i can crop to half the image size and still be as detailed as before.
Have i said before ITS GREAT, even the flippy screen and live view when the shot needs to be taken from a odd angle etc.
But remember improving your technique will probally be a better investment, when i 1st got the 60D i was thinking "mmm love the extra features, but are my pics really any better (except in low light)" then i religiously tracked soem other users with older kit who produced better photo's; i tried to reproduce their work again and agian - and yes now i'm getting better pics - but more from better technques than purley the camera.
Cheers
Stuart