There's a decent group of changes coming with 2.9, as well as a couple minor map fixes. Among these things:
-Blazing Colosseum scripts revised to eliminate the double deep and damaging ground bugs, by evilspacetomato.
-Cyberdemon price raised from 130/115 to 140/125.
-All Enchant-able Units are now immune to radius damage coming from other Enchanted units.
-Adjustments to make Crusaders worth your buck, and cost less.
-Stalker width reduced from 30 to 20.
-Some changes in Virus to make it a little more satisfying.
It seems that less changes are being made in more recent versions. Is this because the product is improving? Hopefully.