Not including a browser is just another microsoft dick move. They don't want a browser on there and don't want you to be able to easily access media without a windows PC so you will buy a windows PC (where they actually make money).
They could add a browser like the PS3/Wii, add UPnP support so you can pull media off networked hard drives and other sources (no PC needed) like the PS3, let you use 3rd party parts to cheaply upgrade your storage (I can get a 750GB HD for the PS3 for about 120 bucks, less then the 120GB Hard Drive on the 360) and store tons of media on the PS3.
The 360 is purposely given small capacity and limited so you have to store your media on a computer (of course only windows computers work). They add in external hard drive support finally, and limit it to 16GBs, less then you can get in a friggin Wii SD card.
I can totally make the PS3 my only device in the living room and use it to do just about anything I want without needing to go back and forth to a computer. Alternately the 360 is like an extender to a separate PC so I have to mess with 2 devices to get anything done (and leave 2 devices on wasting power to watch movies and things like that).
It's just like having to pay to play games online instead of getting it free like every other platform in the world. It's stupid, unnecessary and I'd say indefensible but many people seem willing to defend deficiencies like no wifi, pay for play, no browser, no 3rd party peripherals and all the rest.
Stockholm Syndrome maybe?