Here's a rundown of the new features:
Rework of heatmap for the map visualization: Now heatmap uses a radius of meters instead of pixels, so when you zoom in on the map you also zoom in on the heatmap. Unfortunately, limitation forced us to limit the maximum on-screen radius of the map, but the visualization will warn you when this happens, and inform you what the actual radius is you're looking at.
Time lines for the map visualization: Now you have the option to connect points within the same group with a line on the map. The order of this line is based on timestamps, so its only available if your data contains both location and a timstamp.
New timestamp parser: The timestamp format has been reworked a bit to include support for the ISO 8601 format (used by many devices). We support all parts of the date and time format, except we require a full date. The technically minded can check out the specification here http://en.wikipedia.org/wiki/ISO_8601. Don't worry, we still support all the flexibilty we did previous as well, such as specifying months with three letters, and AM/PM notation.
Dataset titles are now unique in each project: This means no more projects with several "Dataset #1's, but it might also mean you have to change a name if you upload at the same time as someone else, so don't be alarmed!
New symbol order: We have reordered the symbols you get for the scatter and timeline visualizations (the old order will still be there for saved visualizations). Hopefully the new order is more readable, and we will continue to work on things like this as time goes on.
Password and email management: Now you can change both your password and email address by pressing the link on your user page. You can also request a password reset if you have given us an email and you forget your password.
Locking projects: Ever get a project into a good state and want to preserve it for viewing? well, now you can lock your project from the project dropdown menu, preventing anyone else adding or editing datasets.
Curated projects: This is a new flag that we will be putting on projects containing professionally gathered (or otherwise 'clean') datasets. For now you can search for these on the project page once we start using it, but be on the lookout for some changes to the home page in the future.
Lots of other bug fixes and interface tweaks.