It's the middle of the night for Joe so I'll post this. He'll likely have more to add later.
Here's what the current status is. We upgraded the forums to a setup that will allow us to add additional resources to the server on-the-fly. This way we can throw more hardware at it without actually changing servers (limited only to what can be afforded).
Currently we're starting them off with about the same amount as the old (laggy) setup and they will be increased until we find a good medium between what works well and what won't break the bank. This means that you may not see a big performance increase at first, but it will get better over the next couple days (for now we just wanted to get the forums back online).
If you are using http://beta.serebiiforums.com/ to access the forum, there might be broken images on some of the template(s). That's normal and the problem will fix itself once the nameservers transfer and you go back to using http://www.serebiiforums.com/
any other issues, go ahead and post them here.