Oracle SQL Developer 1.5 Early Adopter is out. I have been using 1.2 for a while and started testing 1.5 couple days ago. As this is still not the official release, I would have to say things are going pretty good and no bugs so far.

The new release has a major look and feel upgrade. Compared to SQL Developer 1.2, SQL Developer 1.5 seems to run faster, which is always a plus. Some of the new features that are easy to notice is the "formatting" style. When using the format option, your query gets formatted in a very nice way that makes it very easy to read and follow.

You now have the history feature for every SQL sheet you have open. This acts like a backup copy for your open sheet and you can restore a previous dated one if you'd like, very nice!

Also, a line and column number has been added to the right side bottom of the application to show your cursor position (very handy when debugging).

You can read about all the new features here.
Things you need to know before you start!

You can get Oracle SQL Developer Release 1.5 here.