I created the @wixtoolset Twitter account late last year. The account sat mostly dormant until two weeks ago when I started experimenting with posting to Twitter (tweeting?)from the command-line. After a couple tests, I integrated the experiment into the WiX toolset build process so every build makes a status update to the account. You can see an example here.
Something Rob setup, I think. The obvious, but trivial, answer is to "tweet". :)
I'm not a twitterer so I don't know what we've been saying. But, from a clandestine look, we've only been sending build notifications on it ... the account itself is tracking Rob like a bloodhound and Bob like a lazy guy watching a dude in an airport terminal go about his business. Which is to say, Bob had something like 2 comments in the last week or so, Rob had a dozen. :)
The truth is I'm just experimenting with additional ways to get the news out about new WiX toolset builds. The more people that install the latest builds the better the toolset becomes. So, subscribe to the WiX toolset feed or follow the @wixtoolset Twitter account whichever works best for you. But please do upgrade regularly to help us improve the WiX toolset.