There is a few rumours going around the interwebs that Kindle may be coming out with a colour ereader/Tablet sometime later this year (maybe even as early as June) Of, course it may be just a rumour, but if you aren't in a big hurry maybe try and wait it out until June?
That's my plan anyways, but knowing my luck just as I run out of patience and finally settle on buying a nook color the kindle tablet will be released the next few days.