For many players, the background downloader defaulted to a state of unexpected high activity. You can find a complete explanation of that here. Along with today's patch 2.0.5, this should no longer be an issue.
Where is Global Play?
While Global Play was technically enabled with patch 2.0.4, we did not expose the Region button for Global Play until patch 2.0.5 (today). Furthermore, you will not see the Region button if you have "Remember Account" checked. For most, finding it is just a matter of unchecking Remember Account Name and then clicking the up arrow next to the login ID field. That takes you back a screen and the Region button should appear on the far left.
Don't forget that you can't play in a region that has not yet updated to your version of the game.
Where is "vs. AI" mode?
To play a custom game locally against AI opponents, go to the Custom Game screen, right click on any map you want in the map list and select “Create Offline Game”. This will create a local lobby and allow you to select AI opponents of various skill levels as you could previously.
You can read more about this and discuss it here.
With patch 2.0.5 (patch notes here), we fixed a bug preventing this feature from showing up if you had not fully updated the game files. Please note that the Options/Language tab is only available after you've logged into the game. You cannot change language from the Options button on the login screen.
Actions Per Minute (APM)
A number of players have noted that the APM calculation appears to have changed. We can confirm that there is an issue here, and we're working on a fix that should come with a patch after the release of Heart of the Swarm. Furthermore, we've long had a goal of changing APM so that it is perfectly accurate with regard to real time. We continue to work on that, and intend to have more to say about that in a few weeks.
That Idle Worker Indicator
It's not as easy to notice as we originally thought it would be. We've seen a number of players ask us to address that, and we're on it. Our hope is that with a patch after the launch of Heart of the Swarm, we'll be able to make it stand out a lot more.
There are other issues that we've noticed players question over the last couple of weeks and even today since patching to 2.0.5. At this time, we continue to investigate everything listed in our Known Issues thread.