I use TVrage's (calendar tvrage com) to view my schedule (put your own dots in.) It's not an iCal, and it won't send you reminders but for some folks it might do.
For reminders, you might try Pogdesign, which also syncs with ical and Google (sorry TvRage. Hope you don't mind me talking about other sites. I've omitted the links so my post doesn't get 86'd. People, please Google the sites.)
Also, TitanTV (USA only) has a way to sync with iCal if it still works. I've only tried Pogdesign personally (6 months ago.) However, I have scheduled recordings with Media Center using TitantTV. That was cool, but pointless since the EPG in Media Center works fine. Good for the occasional error I guess. Also good for remote scheduling away from home if you introduce Media Center to TitanTV's file-type ahead of time.
Yes, TVrage is better but I hoped these resources might help some people.