Yup. In the case of Tivo it is either a monthly or one-time subscription. The upside is that it is a Linux box and you can upgrade the hard drive for more recording and the software provided is very easy to use. You can even hack the box and add capabilities such as ethernet and USB connectivity. Yup, warranty voided...

There is a new one coming out next year by a company called Moxie Digital. This is even better as it will become a head-end for the entire house. So you can record the programs and then send it to whatever TV you want, plus it will handle all broadband connections and even stereo (so you can send it throughout the house as well).