At long last my account has been upgraded to the latest version of Twitter's web interface, known as #NewTwitter. It is quite a change from the old site and here are my first impressions:
Desktop client replacement - First off, I must say that I do like the update. It is easy to use, slick, fast and well designed. With all the extra features I can see it replacing desktop clients. For new users there is little incentive to search out, download and install a twitter client and for power users the new web interface has many of the features they require. Twitter.com is still the most popular way to tweet and I can only see this popularity increasing.
Right panel - The new right hand panel has many uses, from showing content from other sites, such as a YouTube video, to displaying whole conversations. It works well, but is a little busy. It would be nice to have a 'hide' and 'display' toggle button, so you could view all the extra content if needed or just concentrate on your timeline of tweets.
External link previews - Although the right hand panel can show rich media from some websites, such as Twitpic photos, most external links still require opening a new window or tab. A mini preview of the website being linked to or even a summary of a blog post could be shown in the panel.
More services - Twitter have integrated lots of third party websites into the new right hand panel, but it would be nice to see a few more, like Posterous for instance.
Personalisation - With so much more information being shown it would be useful to be able to personalise the layout. A modular approach where modules can be shown, hidden and moved around, as used by Google News, would work well.
Notifications - One thing that desktop clients can do and that Twitter.com cannot is automatically notify you of new replies and direct messages. An auto-updating number in brackets next to the '@mentions' tab in #NewTwitter would suffice.
Consuming more - I find that I'm much more likely to watch a video or view a photo now that it can be done directly within Twitter.com without going to an external website. Whether that is a good thing or not, I'm not so sure..
