The reason the NES and Summerboard are not there is that, for them to be installed using the installer.app, the two programs have to be "allowed" to run on the new firmware.
Because you can't download it, you can't set those privileges (so wait for the developers too)
You can install summerboard manually though. I have not tried NES but will help anyone that needs it.
Download summerboard here:
http://www.nullriver.com/~zigzag/SummerBoard.zip
Ok... Install SSH on your phone, and log into it using an SFTP client. (I use CyberDuck)
Read carefully now, and copy the files to your iPhone from the Summerboard folder as follows:
SummerBoard.framework -> /Library/Frameworks/SummerBoard.framework
SMBPrefs.app -> /Applications/SMBPrefs.app
Themes -> /var/root/Library/SummerBoard/Themes
com.apple.SpringBoard.plist -> /System/Library/LaunchDaemons/com.apple.SpringBoard.plist
Make sure that the plists permissions are as such:
-rw-r--r-- 1 root wheel 704 Oct 9 20:00 com.apple.SpringBoard.plist
you now have summerboard prefs. have fun!