I'm glad they're working on fixing some of the limitations.
the reasoning behind it was to synchronise it with the char limit in a single SMS message, but does it really have any relevance today?
I think that worldwide it must have some relevance, but I'm of a different demographic. I almost never use SMS.
The Twitter interface overall needs some UX work. I like to use Lists, eg... lots of them, because Twitter's users cover a wide spectrum of my interests.
A simple thing like adding someone to a List, though, is peculiarly non-intuitive on Twitter. Normally, in the dialogue box, I'd expect to check applicable checkboxes, and then click a "Save" confirmation which could also close the dialogue. The way Twitter has set it up, though, I must simply close without saving... an action which in most software causes loss of data... so I'm a bit uncomfortable whenever I do this on Twitter.
Also, Lists can't be alphabetized, renamed, or easily combined.
The heart "Like" is the closest thing Twitter has to saving favorites... again, not helpful if you like to track a broad range of topics. By keeping Twitter completely in the here-and-now and not making it more useful to people who can't or don't want to keep up with the very large flow, Twitter (and, to some extent IMO, Facebook) risks losing a potentially valuable type of user.
Search on Twitter posts is difficult because of 140 characters are hard to parse for long tail queries. etc....