The 7870XT is the crippled version of the 7970/7950 and is based on a superior architecture than the 78xx series, and isn't really that expensive either. We haven't had any news of upcoming 8xxx series desktop GPUs either, or at least not on Tom's Hardware. A 7870XT will be a very good investment indeed.
There are other versions of this, look up the Powercolor Myst Edition
It's also known as the 7870 Myst, or the 7870 Tahiti LE. They're all the same card, and they're disabled 7950s based on the tahiti core; thus much faster than a normal 7870.