wpegg: I believe that there has always been a timer on the interface.
P1na: Maybe, I just didn't notice until now. Either way, it came right at the same time. I still just now forced myself to finish the prologue, and the second mission wasn't timed after all; but I still don't feel like starting the main story at all.
If you've bought it, or are in a position where buying it will not particularly push your finances - play the main story. At least start the main story, it's got an awesome opening.
Also, as I separately said, this co-op mode is really good fun, though I think they need a few more maps, as the current pool is already looking a bit shallow.
Klumpen0815: It would have helped if the title had "Starcraft 2" in the title, because I didn't know that it's about some Blizzard DRM-fest either.
Did they seriously divide Starcraft 2 in multiple parts to sell it more often? How many times do you have to pay and do you need all of them in order to be able to use the (undoubtedly online-only) multiplayer mode?
In retrospect, I agree (if only we could edit titles). However I assumed people were up to date on things that it appears they were not concerned about.
In answer, you have to pay for three games, two att full price HOTS was at high cost expansion price of about $40. This one does add quite a lot on though, and is standalone so you can buy it without the others.