The recent Dreamcast Collection compilation disc for Xbox 360 featured Sega Bass Fishing, Sonic Adventure DX, Space Channel 5: Part 2, and Crazy Taxi. These games are now up on Steam, and can be purchased individually at $8.99 a piece or bundled together for $29.99.
Assuming they work as intended (you'd be surprised), these are mostly decent enough to justify the price. And they're upscaled and widescreen-ified, to boot. That said, if Sega only puts out these re-releases and nothing else from the amazing Dreamcast library, talk about a slap to the face.
Here's hoping this is only the beginning of good things to come.