No, its not that it will be definitely be increased to 2MB, it's just that it is theoretically possible for it to be increased to 2MB: the block size is a parameter voted for by the witnesses and the max allowed size they can vote for is 2MB.

Currently they are voting for 64K size blocks and this is plenty of space for now, IMO.

But we want to be sure there are no issues in the future if witnesses vote for a larger block size (this would become necessary if Hive starts having to process a lot more data), so we're doing testing related to that now.

A little while back, we began developing 'flood testing' code to test how the Hive network will behave under much, much larger transaction loading than we currently have.

We recently used this flood code to ensure that increasing the allowable transaction expiration time to 24 hours would not open up any vulnerabilities for the network. Now we are using it to test for issues that might occur if blocks got increased to 2MB (not surprisingly we've seen some issues since this was never tested before under this kind of heavy loading condition, but they need more analysis).

Just FYI, I think one of our devs is going to write more about this code and what's he found in a bit.