Hmm. Maybe with the R580+, the X1900XT was going to slot into the upper-mid/lower-high range, but they're going to replace it with this card thats less expensive for them to manufacture? A $300 price point for this wouldn't be too bad with current prices. It should be a nice bit faster than a GT, but still a good deal slower than the XT.
Here's what I think would sound reasonable:
X1950XT $400-$500 (depending on how much they've put into it, and XTX designation)
X1900XT $350 (until stock clears out)
X1950GT $300
X1900GT $250
Maybe Hellfire 1 at $300, Hellfire 2 at $350, and then X1950XT/X for $425+
With the compositing chip onboard, they can now better compete with SLI. Maybe run a promotion to get people to pick up a Crossfire board and two of the Hellfire cards for $600-700 depending on how high end of a board you get.
I don't think this means that the Hellfire cards are going to be the new top of the line, but will stake out the same range as the current X1900 cards, but will be cheaper for ATi to produce.