I'm glad to hear that you've decided to start trying to communicate with them again! I already own Aquaria, but the larger audience sure couldn't hurt.
Valve's practices with Steam lately definitely have been questionable though. First we have the Braid guy Jonathon Blow echoing your sentiments on how hard it is to get in contact with them. Then Capcom goes and canceles their Steam release of Bionic Commando: Rearmed. Then one of the PAX 10 guys I talked to said similar things.
Now we have EA games showing up on digital services other than their own EA Downloader - something I didn't expect to happen - yet their games still aren't showing up on Steam despite a great distribution relationship between Valve and EA.
It really sounds like Valve needs to expand - you look at them, 150 spread between Steam, multiple games, and support, compared to a company like Harmonix that has 280 people working on Rock Band and not much else...it gets quite clear why Valve is having such supposed troubles. In the case of Aquaria, why *WOULDN'T* they want to put it up? Even if it only attracts a small audience, it's not like they'd lose money from it.
Anyway, good luck in all of this.