+Michael N Sutton
Snapseed got already announced and demonstrated for Android at CES - so I guess we should see it soon.
A useful replacement for Camera+ might be Vignette. I also like ShotControl which is which is pretty new but offers a very quick and handy exposure control.
Instagram is coming, but from the last interview with them (gizmodo website) it sounds like they're still busy with scaling up their servers. They seem to be a bit afraid they might not handle such a big grow from one to another day when the release their Android app. The Android release might double their amount of users in a very short time.
A good competitor to it is StreamZoo which just launched 2011. They also offer a little extra features like WebInterface, Video Support and a social gaming part and the community is very friendly.
Don't know anything about those other two apps so I can't say if there is something like it.
A little bonus for Android is Adobe Photoshop Touch which isn't available on iOS yet.