We've been considering putting together an off-season patch that could follow the WCS Finals at BlizzCon, in hopes of increasing diversity in StarCraft II. Before we make any big decisions, we’d like to play some balance test maps with you, to see how some stark changes play out. As always, this isn’t final. This is testing.

So here are the changes we're currently considering testing:

Mech ground and air attack upgrades combined
We've been looking at this for a long time now, and it feels like a solid step in the right direction.

Widow mine splash radius decreased from 1.75 to 1.1
We'd like to push out the Widow Mine a little bit and bump up the Siege Tank so that bio play becomes more interesting. Ultimately, we believe a mix of Widow Mines and Siege Tanks with your bio army will be a lot more fun to watch than just Widow Mines with bio alone.

Siege tank attack period decreased from 3 to 2.7
Bio play may be more interesting with the Widow Mine change and this buff. Not only that, we believe Terran mech armies can be a lot more viable because faster attack speed naturally means Siege Tanks will be better against their hard counters.

Oracle cost decreased from 150/150 to 150/100
Protoss feels like it has been playing too defensively (outside of Warp Prism harasses). We’re seeing Oracles only being used in the early game, and not much during any other stage of the game. We hope by reducing the gas cost of the Oracle, they’ll be used more throughout the game.

Dark Templar movement speed increased from 2.813 to 3.375
We believe that Dark Templars could be more interesting to watch if it's not just a matter of the opponent being prepared or not. Even when their opponents are prepared, we believe by increasing Dark Templar’s movement speed, there could be more interesting interactions, such as dodging out of detection range more often

Roach speed upgrade also increases the burrowed roach movement speed from 1.41 to 2.25
We just don’t see Tunneling Claws coming into play much. There’s some really cool micro potential with burrow-moving Roaches, and we'd like to see how this goes in a test map.

Again -- none of these are final adjustments, and we’re considering others. We're probably going to publish a balance test map soon, so please give us your feedback as soon as possible.

As always, thank you very much!

BNet Forums Source
I like all the proposed changes except those for the Oracle and Dark Templar (Blizz wants Protoss to be even cheesier than it already is) and for the Roach, because it feels too random to make a change like this.  Even the TL.net polls say that the proposed changes to the Oracle, DT and Roaches are a "thumbs down".

I think you're being bias twards protoss ... like all the buffs apart from the protoss ones?? seriously? is there any legit reasoning behind this? cheese is cheese and all races have them.

I like all the proposed changes except those for the Oracle and Dark Templar (Blizzard wants Protoss to be even cheesier than it already is)