Comparing across review sites is never the best idea.
Unfortunately since it's only a preview it misses a lot, especially when it comes to comparisons with other cards (things like the HD5830, HD5770 and HD5770 Crossfire, and maybe some lower end SLI setups) would be nice. HD5770 1GB is about the same $300 as an HD5850.
One important thing to consider is that it's not always as bad as it looks, as I already noted.
While it gets soundly beaten by the HD5850 at 2560x1600, at lower resolutions it competes without too much issue for the most part, and given that it's (arguably) overpriced at $280, when the price (hopefully) becomes more reasonable, then for a medium end user (i.e. 20~22" monitor), it might not actually be that bad (especially at somewhere around $250), since an extra $50 for an HD5850 won't get you much at 16x10/9, if anything.
The further down you go, the less you need to realistically look at higher end resolutions, because this sort of solution, or the HD5830 or HD5770 aren't as likely to be used at the higher end.