Well, it seems we finally know why TiVo was waxing poetic about software in recent months -- it's the way the company primarily plans to charge for its DVR hardware from now on. Following a week-long experiment of free-on-contract DVRs conducted last month, TiVo's opening up subsidized and partially subsidized pricing tiers to the entire US for those willing to chain themselves to a pricier $20 monthly fee. You can now get a TiVo Premiere for $0 on a two-year contr