Not true anymore. Genesis/Faroudja is far behind Gennum VXP, Realta HQV and the new NSC chips when dealing with 1080i signals. Owners of scalers using those new chips are the "niche" market for the 970HD.
Those new chips can do everything the Faroudja chips are doing for 480i, but they can also do inverse telecine and per-pixel motion adaptive de-interlacing, and frame-rate conversion, with a 1080i signal. Something the "old" Faroudja 23xx and Sil504 chips can't do.
For example: the Anthem D2 (Gennum VXP), Vantage HD (Realta HQV), Algolith Dragonfly (Realta HQV), Crystalio II (Gennum VXP), Lumagen Radiance (Realta HQV)... and more coming... And also some projectors that are now integrating those new chips: Marantz S4, upcoming Optoma 1080p, Cinetron HD900... etc...
Owners of those high-end scalers and projectors are the people that will buy the 970HD to get clean 480i over HDMI for cheap.
With the new HD-DVD players from Toshiba, those new chips are a must to treat both 1080i and 480i, and avoiding doing "bob" (and loosing resolution) with 1080i. Also, DCDi does not apply with 1080i, but the Gennum and realta chips are doing it for 1080i also.