I took a look for you and Windows takes up a touch under 7GB and the entire Program Files (including Office) takes up 800 Mb. And you do know that there is a micro SD slot for additional storage?
An interesting article in WSJ says that the 32 GB Surface without keyboard is sold out on the US and all other countries where it is sold.
I am starting day 3 with my Surface and here is my take on it.
1.) MS is trying to encorporate their Phone interface (used to be called Metro, but I think they have now changed that) to all OS flavors. It works well with touch screen but not so much with a conventional monitor. It is a real PITA administering Server 2012 via a Remote Desktop client.
2.) I don't rememeber Win 95, but 98, XP, Vista and Win 7 all had a desktop START button on the lower left. With Win 7, you could "pin" applications to the Start menu (or the Task bar) for quick access.
3.) The Win 8 Start screen is simply the Win 7 Start menu pre-configured as "Tiles" with a collection of apps MS thinks you may want. If you don't need them, just unpin them. Then go to All Apps and pin what you do want to either the Start menu or Task bar. Once I got that concept, everything started to make sense.
4.) Multimedia has never been a Windows strong point. I don't see that changing anytime soon. I'll keep my music on my Galaxy Nexus.
5.) However, I do see this as a productivity box where I can actually do work. I am not a touch typist and I can actually go faster on the Touch Cover than I can on a traditional PC keyboard. My wife / partner really likes the Type Cover, so chose the one that works best for you. Don't forget that there is a USB port and you could plug in a traditional keyboard, in needed.
6.) There is one app missing now that keeps it from being a laptop replacement for me: Cisco AnyConnect. That is a SSL client and I don't see why it won't be released in the near future. In the interim, I'll make do with PPTP. Another app I miss is Slingplayer, but since there is a Phone 7 app, I suspect that will also be released soon. FYI, my Cisco engineer has told me that the Cisco VPN client we are all used to and is baked into the iPad is End Of Life and will be replaced by the AnyConnect product.
Is this a perfect device? No way. But IMO, it is a darn good start by MS in what the fanboys have proclaimed as the "post PC age."