Great iconset but I wrote a small list over here, you can work on it all once when you have some free time :

The call log icons in and outgoing calls.. you can use just the arrows instead. the icon is small and is wasted by a huge phone icon and a very small arrow

The Conversations app and contacts ... The Facebook IM icon,
you can use the plain Facebook icon instead of the 3 coloured guys and the very small f letter.
Because the MSN and skype icons are plain as well. so that is more consistent

The contacts App.
The email icon for the email field has an asterisk for no reason.
The OFFLINE icon should be grey instead of red. As red usually implies online but busy. So Green--> online Blue---> away.. Red-> busy and Grey--->offline

The Camera app... The 4 arrows for the focus point looks very weird, try plain lines!
The Go to gallery icon: try using the normal Gallery icon with an arrow instead.
The close application icon... try going for the plain X icon.. the arcade style power off is just not right.

The Photo gallery
The crop icon is confusing.. u can go for the normal crop icon.
the delete icon here as well as in the email app can be changed to trash can.

The rotate icon can be the arrow only. because when you press it.. the other counterclockwise icon appears... so you can just use the mirror image of that for consistency.

The tags icon... well u can just use a normal Tag icon.. because the arrow and the gear implies settings of some sort rather than tags

The status bar
Well the Wifi icon, Bluetooth and the GPS must loose their background and occupy their maximum space... it's a small icon already so wasting it in a background makes it hard to see colored spots

Some people are also not satisfied with alarms icon.. .. a bell with the clock instead fits the Alarm function.

I have a problem with the Calendar Icon saying 12.....
because that only happens once a month... so I'd prefer maybe a timetable sorta icon...

Overall a great compilation though!

I am also totally up for doing some icons for you.. I am good with vector and pixel editing for around 8 years now.
I've never done GUI but I've a good idea.

Thanks for this great Icon set, It feels like a whole new n900 for me..!!!