I'm largely to 'blame' for these new changes
The message link went north for two reasons. It was the only link in the left hand margin that was to a 'personal' area, ie. something that accesses your own information, rather than general things. Secondly, there have been a few threads in the past about some of the popular areas of the site not being easy enough to access (specifically people missing the CP link). So with the change to include them directly under the CP tab, we decided there was even more reason to move the messages link up there to keep all personal links in one area.
Hien, it was not the intention to replace it with a graphic (originally had something like that), but considering the feedback, maybe it's a good idea
Isa, the text is in the same size as the 'Welcome to Travellerspoint' text that shows when not logged in. I like consistency, so wouldn't increase the text, but a graphic should take care of that issue too