There are a few things in installer.app I'd really like to see:
1. A version # check for apps.
Yes, I know installer has added a date check, and it's "soon to be mandatory", but for now, not everyone has it, or knows how to do it correctly.

I hate installing an app (typically from it's main repo), and someone else (Ste, or Shai, or someone else) puts it on their repo as well. Then, when an update comes out, and I update the app, the OLD version is shown as an "update" in installer, from the OTHER repo.
I also ran into this today: I had Screenshot 1.2.1 installed, from Ste's repo. It never showed an update, but I see that 1.3.0 has been released from the "official" repo of Robota Softwarehouse. WTH? Why didn't installer show it as an update?
2. The ability to scroll through the "All Packages" by first letter, sorta like the phone app or iTunes does, with the alphabet down the right-hand side of the screen. If I'm looking for, say, Screenshot, and I can't remember where it is, I have to go to "All Packages" and scroll through everything by continually flicking my finger to make it scroll.
3. The ability to selectively HIDE updates. In other words, a way to tell installer.app to ignore an update for whatever reason. This goes back to #1; I should be able to swipe left on an update it shows, and have an option come up that says "ignore this update?", and say yes or no to it. Installer would then not show the red 1 over it's icon, since I've told it to ignore it.