I got a laptop with Intel GMA4500MHD graphic card. I installed Kubuntu 10.10 [64bit] on it successfully, but... it runs only in shell mode, not even trying to run KDE itself. How to fix?

I suggest contacting the appropriate Kubuntu support mechanisms for this, as it is likely a fault in the graphics stack. Checking /var/log/Xorg.0.log would be a good start however. dmesg may also prove helpful.