I can't remember where I read it, but I've read a couple reviews of satellite "broadband" service. Anyway, the general consensus was that they were not worth the investment now. The reviews showed that on average you got a connection speed of around 5-10 KB/s, only slightly faster than a 56K modem. And there was lots of complaining about getting disconnected. Other complaints were download limits, like if you downloaded more than 350 MB/hour you would get limited bandwidth for like 12 hours. It made me very weary. I'll see if I can't find some links for you.
Satelite is great if you are doing a lot of large downloads. My mom has DirectPC and it has incredable download speeds for large files, but for surfing the web it is no faster than a modem because of the 56K up. I hit as fast as 320 kb/s downloading files from Microsoft's site. If you have the money to get the two way dish then I would go for it, but the $800 cost is probably not worth it unless you absolutely cannot get DSL or cable.
Hold out the few extra months or so and get DSL or cable. It will be much cheaper and you will be able to play online games, upload files quickly, and surf faster.