...Unless someone fashions an app and cable to make it into an external monitor etc for DSLR-cameras.
I'm not sure it actually has a "live view" function, but I remember really wanting to get this back when I still had my D90.
Had to sell the iPad 2 for gas money last month, but between work and this year's tax return I was able to pre-order a new one. Picking it up at my local Apple store after work. Went for the same 16GB Wifi version, but I kind of wish I had gone for a 4G; 4G on my iPhone 4S is pretty impressive.
I was dubious about the iPad when it was announced, but the last year with the second generation has made me see just how invaluable it is.
Personally, I use mine a lot to stream media from my computer. I ripped my entire DVD library for iTunes, so between that and a little app called Air Video, I can watch pretty much anything on my computer from the comfort of...anywhere in the house.
The only downside of my current setup, is that my otherwise portable Macbook Pro, is pretty much chained to my desk to act as a media server. I think my next Apple purchase will be a Mac Mini to take over media server duties. Eventually I'll be able to afford a decent TV, and I'll want a Mini to hook up to that anyway.