You've gotta remember, Twitter is in a very sticky situation at the moment! One one hand, they know their architecture isn't perfect and will be rebuilding it

You've gotta remember, Twitter is in a very sticky situation at the moment! One one hand, they know their architecture isn't perfect and will be rebuilding it to cope with more users. But on the other hand - they are a small team which is trying to keep it up in its current state, and cant just decide to close Twitter for a few weeks/months while they work on the new architecture, people will defiantly move to another service, and Twitter is dead.