It's an interesting move, my concern would be that Twitter is talked about enough by name that people know the name but might not necessarily use the site and w

It's an interesting move, my concern would be that Twitter is talked about enough by name that people know the name but might not necessarily use the site and will no longer make a connection when they see Twitter online (outside of Twitter.com) because it's a logo that doesn't represent the name. For example if someone watches CNN and they hear Twitter mentioned they might not think "that's something I should check out" but then if they're browsing their favourite bands website and see "Find us on Twitter!" they might think "I heard about this on TV and my favourite band uses it, I should check it out!". With the logo not representing the name they remove the possibility of this happening. Maybe it's an inconsequential amount of users but there are multiple products and brands I've heard about but not been compelled to check out until I saw them mentioned somewhere else.