I just picked up a Dishplayer 500 and turned off our digital cable. I have to say that I love this device. It includes WebTV and what the Dish Network calls "Personal TV" which has features similar to TiVO and ReplayTV.
You can record up to 17 hours of programming on the Dishplayer. The included remote has a "record" button that you can push while browsing the program guide. You can press it twice to record that program every week. Recorded programs are listed in the Personal TV home screen and include the original program notes that appear in the program guide.
The recording is fully integrated with PPV. If you select a PPV movie to record, it prompts you to approve payment first and then schedules the recording. The movie remains on your Dishplayer to be viewed as many times as you like. Pause, rewind, etc. all work on recorded programs.
The recording feature also works in the background on live TV. I was watching a football game the other day and wanted to watch a long kick return again. Press the rewind button (I'm not sure what the limit is, but it is more than 2 minutes) and then watch your own replay. The Dishplayer is still recording live TV, so you can fast forward or use the 30-second skip button to move through commercials (or timeouts) until you catch back up to live TV.
WebTV is not that great in my estimation. I do however like using the wireless keyboard to type in the search for programs like "New Yankee Workshop" without having to struggle with the remote buttons.
The programming on the Dish Network is adequate for our needs.
The only feature that I haven't got working is the optical audio output to my Sony receiver.
I know a DirecTV with similar features is coming mid-year or so, but I enjoy having this Dishplayer 500 today.