I can't friggin wait. SPOILER ALERT: Do not read on if you haven't watched up through Season 4, you are bound to see someone who posted something that may or may not have happened at the end of Season 4. There, let the fun begin.
I have seasons 1 -3 on dvd, but have only seen a few episodes of season 4 -- although one of the ones I did see was the season finale, so no concerns about spoilers for me. Would very much like to see 4 come out on dvd.