It might be more productive to flood Tivo with emails, as I think their US patent infringement law suits are the root of the problem since Pioneer is indeed making and selling DVDRs everywhere else, just not the USA.
Since Japan also uses NTSC and they have already developed units with digital tuners, the March 2007 deadline for shipping analog tuner equipped units obviously isn't the problem. Also, some Canadians have received discount coupons for new 2007 Pioneer DVDRs to be released in a few months, so Pioneer apparently plans to sell in Canada where you cannot get Tivo service...hmmm...seem like a pattern to you too?
Others have posted they think there just isn't a big enough market for DVDRs in the US because Pioneer (and presumably others) lost money on the DVDR market in the recent past as they reported, but if that were the case why sell in Canada which is a much smaller market? Unless it's because Canadians are willing to pay more and/or return fewer units, (maybe, but doubtful,) I think past losses have to be mostly attributed to design flaws, (like the TVGOS mess) and therefore maybe the lack of availability of premium DVDRs in the US has more to do with the Tivo litigation and/or DRM pressure from movie industry lobbyists.