Should a laptop replace a desktop?

I’ve been thinking of getting a laptop to replace my desktop, but I don’t know if that’s a good idea.

So far I’ve stayed away because of money, and a lot of it was the battery time these laptops have is just a joke.
Anything under 5hours of battery time is just a total joke for me.

At my desktop I have:

  • AMD 3200+ (2,00GHz)
  • 1,5GB DDR400
  • GeForce 6600GT 128MB DDR3 PCI-E
  • 80GB + 80GB + 200GB
  • 1 external IDE kit with a 20GB IDE hdd in it.
  • DL DVD writer
  • WiFi 802.11g
  • 17’’ CRT(VGA) + 19’’ LCD(DVI)

It’s a pretty good PC so going over it with a laptop would just be a hole in my pocket for a long time.
I’m usually on MSN, WOW, Photoshop, listening to music or watching a movie. So most of these are intensive aplications.
From what I know that kills battery time.
Any pointers towards what I should look for, or change for better performance?

Anything I should avoid?

Tech Shopping tips & tweaks…