For those waiting on the next release of
StarCtaft 2, you can try and
get into the closed beta right now.
Heart of the Swarm's multiplayer portion is being tested and you can opt in to try to be one of the select few to test it out.
Now, only the multiplayer aspect in play as the folks at Blizzard want to test out the new features and units for all three sides. There's no time table on how long the test will go nor how many people they will pick, but if you are interested, just opt in in your profile on the Battle Net website.
And if you didn't pick up Wings of Liberty, fear not as that's not a requirement to jump into the beta of Heart of the Swarm.