With only 140 characters, the 9am tweet couldn’t communicate much about the nature of how the ‘range anxiety’ problem would be addressed. All we know for sure is that it will be done via a wireless software update that is engaged while the car is connected to the internet, and that it will affect the “entire Model S fleet”.
This counts out the possibility that the announcement would reveal any hardware changes, ‘supercharger’ technology or location upgrades. Whether these software change do indeed live up to the superlative ending of range anxiety remains to be seen, but will likely be a marked improvement. We'll just have to wait and see.