To be honest: If you look at latest (flat-)TV sets and their way to deinterlace and scale the picture, I would prefer to get this done by software e.g. by using spline resize algorithms (see e.g. http://audio.rightmark.org/lukin/graphics/resampling.htm) and advanced deinterlacing options (see e.g. http://home.knuut.de/MWieser_/vf_raw_ntv_8) known from xine and mplayer.
Deinterlacing & scaling is much more than just "comb-effect defiltering". Additional crispness filtering needs to be applied. So far all software DVD players has failed on this. (Windows side)
For more info see: www.hqv.com (Hollywood Quality Video)
Benchmarking: http://www.hqv.com/benchmark.cfm - See difference of good and bad ones - My LCD TV's Faroudja beat all SW decoders on picture detail keeping - Yamaha cheap DVD player with scart & rgb - computer with monitor
Of course you can ignore my comment because I haven't tested Mplayer as well as "MWieser", it is possible that Mplayer deinterlace with denoise etc. is better than Windows side (VLC, WinDVD, Nvidia purevideo decoders).
Unfortunately, those algorithms need processing power, processing power is expensive, and this will make this hardware really expensive.
And more noisier! (Or without noise even more expensive :)
Regards, Jori