Tempests are awesome.
I was sad to hear that SPAZ got turned down for Steam. Valve really said they had too many indie space games? That's ridiculous. There's no such thing! SPAZ is a lot of fun, kind of like Star Control. Just a bit too grindy for me sometimes, but definitely good entertainment. Better than many of the AAA titles on Steam right now ...
I'd like Starfarer to end up on Steam, too. I'd be tempted to buy it again just to have it there (with silly achievements!), assuming I can scrape together the monies for another copy. Valve seems kind of random when it comes to accepting games, but I guess they have a system.