The surface comes in an RT version that is aimed squarely at kids and consumers, and a Pro version that is more powerful and designed for business use. This is a full functioning PC and you can run most any windows application on it. There are some video issues with certain apps, but those are reportedly rare. Battery life was sketchy on the original Pro at a practical 4 hours, but the Pro2 has addressed that via a more efficient processor, and a keyboard with a built in battery pushing battery life to a respectable 22 hours.
Unfortunately there is no option for an internal modem like the iPad on any of the Surface products so you are limited to Wi-Fi. They offer 64 – 512 SSD storage. As far as size recommendations, it really depends on the user, but I currently use 115MB of the 128 available storage on my iPad and windows apps hog more space so I would personally go with the 256 or 512 assuming you can wait for the Pro2. Microsoft promises an Oct 22nd release date and you can already reserve them here:
So will the surface make it as a platform? Could you end up with an unsupported device? Hard to say, initially it has been a flop despite the quality hardware and what is generally considered a great user experience. The iPad and Android tablets have a long head start on Surface, but if anybody has the staying power to make it work its Microsoft. Even if Surface does not make it, it will be years before Microsoft will End Of Life the product, so you will likely be using something else before it becomes an issue.
Bargain Alert! Microsoft apparently has 900,000 in unsold surface inventory on hand, so I expect some fire sales on the old model in the near future.
Here is a good review of the Original Surface Pro:
This is a good article that will give you an idea what to expect and I recommend you read the whole thing.
And an update on the Surface Pro 2 (new version yet to be released)
This article will show you the difference between the old and new.
Surface Pro (original)
64GB Storage $800
128GB Storage $900
Surface Pro 2 (new version)
64GB Storage $900
128GB Storage $1,000
256GB Storage $1,300
512GB Storage $1800
See the follow up Article: The Underwhelming Surface Pro 2 – Hands On Review