Apple is rumoured to unveil a refresh in the iPad lines along with a new keyboard cover case and possibly even the fabled "iWatch". It's also believed that their newest iteration of Mac OS, Mavericks, should be released as well.
Apple has done an excellent job with listing these new updates on their website this year so I won't go into any detail. Feel free to browse their site for these new features and updates in all their apple glory. Apple will be streaming their keynote live via the Apple TV and their website. Be sure to tune in and watch.
If you have a live-blog you'll be following along from feel free to leave a link to it in the comments below.