Rumours are circulating that the PSP slim will be launched in the UK before Japan. Whilst this would be a nice change for the UK to have a launch before Japan, I doubt it will happen. There has been no official word from Sony on this matter as of yet.

The PSP slim will be launched in September (rumoured August for UK), for approximately 114 in Japan, but with reduced battery life, and barely any difference is size, is it really worth it?

With the apparent added memory, the PSP slim would be a homebrew developers choice, but it may be worth avoiding if it lacks any real changes. 

If I had to get one though, it would be the silver one... And I'd probably just end up selling it, I barely use my PSP as it is!