The change is a hell of a lot more than a layout and skin - it's basically a whole new version of phpBB (the base software that both the new and old forums run).
You'll generally be seeing more of this type of forum pop up as phpBB3 gets more widely used and adopted - it was released in December 07 so I've waited a bit before converting it over as well as using my other forum at
WWRY-London as a test-bed to see if it's stable and easier to use - the feedback I got on there was that it was pretty good so I submitted it to James as a possible idea, and then ran the final skin past him before I took the old forum down and converted it over.
In the long term, phpBB2 will eventually be discontinued and I'll have to convert it over, and in the meantime the forum would have grown even more and it'll be even more of a headache to convert.
Yesterday I had two attempts - one failed because the database was too big, so I had to convert my Linux machine into a temporary web server including PHP and MySQL, back up the old database, restore the old database to my PC, run the conversion on that, then export the converted database and import it back to the main online database server. The second attempt worked.
Comparisons between phpBB2 and phpBB3 are here:
http://www.phpbb.com/about/features/Once you get used to it, it'll be fine. I've been using phpBB3 for the last three months and it's definitely easier to both use on the user side and also to maintain on the admin side. As I've already said, I personally think the new layout is more stylish and grown-up than the old one.
As I said, I'm looking at alternatives. The outer curves thing is my design, the forum curves are phpBB's - both use different techniques so all I did is just wrap the forum in the UK Thrash design.
