yeah bu it may cost extra
Check to see if it will work first. The cell system/computer system is different in the UK and Europe from the US and it may not work on their systems.
An iPad that you buy in the US will be just as functional as one you buy in the UK. Remember that you have to get a power plug that works in the UK.
UK starting at - £399 US starting at - $499
A new iPad will work with 4G LTE in the US. You will want to get a micro-SIM for a US-based data plan to keep the costs down.
The only difference between the US and UK iPads (See links below) will be the network to which the 3G version connects. And also I believe the keyboard is different
it is out
This depends. First off, it would need to be an AT&T model, as Verizon models do not use a SIM card. Also, it depends on the UK carrier. Most would be compatible with AT&T's network, so yes, you should be able to use a US iPad 2 with a UK SIM. Although, take note that the iPad uses a microSIM, so the UK SIM card will have to be cut down to fit into the iPad.
In the uk it will come out on march the 16th
all previous apps do work on the iPad but some are beginning to be designed especially for them. You can purchase them straight from the iPad or from the iTunes Store.
In April of 2012.
US
You can order an iPad at store.apple.com or at most electronics stores that carry Apple products.
Yes there is an iPad 3. It was released in the US, the UK, Australia and eight other countries on March 16, 2011. The iPad 3 will be released in Austria, Belgium, Ireland, Luxembourg and 20 other countries on March 23, 2012. Please see the related link for more details.