For those who didn't watch the announcement, CCP is planning to change some fundamentals with regards to how warping works so that ships with a higher max warp speed will actually accelerate into warp, and decelerate out of warp more quickly.
I think that this is going to change the dynamic of all manner of ship travel in EVE in a way people don't entirely realize yet.
Small ships will now have a very clear, and definite advantage when it comes to fleet movements. Larger ships will not be able to 'run away' as easily, and these merry jaunts through low-sec that I've witnessed many, many times will end abruptly when the smaller, faster ship catches up to and tackles its target.
The second change on my list would probably have to be the cyno jammers. A while back, the idea of implementing cyno jammers as a Faction War upgrade was tossed about. I admit, I like this implementation much better, as it can be used by anyone, anywhere that cynos are legal.
The ability to prevent a cyno from being lit within a 150K radius will definitely have its advantages, and will definitely be the catalyst for some changed gameplay, I would say. Probably the first thing we were warned about after we announced that we were moving to null-sec was that we could expect every solo pilot to have a cyno --and to have a fleet waiting to back them up.
The third change on my 'top three' list, would probably have to be the changes they are making to interceptors. Interceptors will now be immune to any sort of warp bubble.
I think some of the other ship balancing will also be good --particularly to electronic attack frigates. However, we'll have to wait and see the details before the jury is out on those. =D