Hopefully the summary is clear, I have also included a screenshot from Netbeans 6.0 Beta 1 on Mac OS X in this issue's URL to illustrate the issue.

In Netbeans 5.5, pressing enter while inside a string in Java classes causes the editor to close the string, append the '+' character, jump to a new line and 
start a new string indented properly, placing the cursor at the beginning of the new string.
Like this:
String test = "A very long string which needs to be split into" + 
                    "[CURSOR]

But in Netbeans 6.0 Beta 1, this happens:
String test = "A very long string which needs to be split into" + 
[CURSOR]      "" +

Which is not nearly as useful, and I cannot imagine this being a design decision.

Steps to reproduce:
1. Create a new Java Class in Netbeans 6.0 Beta 1
2. In a method, assign a String to a value enclosed in quotation marks ""
3. Press enter while inside the quotation marks

Observed on:
Product Version: NetBeans IDE 6.0 Beta 1 (Build 200709141330)
Java: 1.5.0_07; Java HotSpot(TM) Client VM 1.5.0_07-87
System: Mac OS X version 10.4.10 running on ppc; MacRoman; en_US (nb)