Apple has confirmed that the iPad 2 launch in the UK is still planned for this Friday, March 25, according to TechRadar. There was concern that the launch would be delayed due to supply issues, but an Apple spokesperson apparently says that the company is still following the date listed on the website, which means the UK will get iPad 2 on Friday afternoon. The launch has definitely been delayed in Japan due to the Sendai earthquake and its consequences, but supposedly (according to an Apple Store employee), it's on everywhere else, including Canada.
If you are trying to get an iPad 2 somewhere in the world this weekend, be warned that the international launch will probably suffer from the same issues that the US launch did, with long lines, long waits and not a lot of solid information to go around.
Update: We've heard from sources connected to Apple's sales operations that there is no way iPad 2 inventories can be effectively shifted from one country to another; each country's product is unique in terms of regulatory certification and the back cover part, so once it's built for a place, that's the only place it's going to be sold. If manufacturing was going to be adjusted to shift the balance of iPad 2 production in favor of US models, that call would have needed to happen several weeks ago -- before the US rollout and corresponding availability crunch.
But aside from all of that trouble, here's hoping you get the iPad 2 you're looking for. Good luck!