Quicksilver is back under development - the latest version is 1.1.2, and the last commit at their repo[1] was five days ago... Not on fire, but there is stuff happening.
Also, you may like Moom[2] for window management - sucky name, but the feature set makes up for it ;)
This doesn't make sense - the apps that aren't in the list of the top 300,000 downloaded apps may not get many downloads as far as we know, but without further information, how can you arbitrarily declare that as the threshold for "zombieness"?
Realistically though, it is really hard to get some attention in the App Store nowadays, and Apple really should build some mechanism into the store to combat this.