For those of you that are crashing, what is the size of memory that GW2 is using when it crashes? You can view this if you can ctrl +alt + delete out of the game when it locks up. If it is above 1.5g then you might be experiencing an issue with Windows. Windows by default, I believe, only allows applications to use up 1.5g of memory. You can override this though. Here is a link to show you how to do this:
http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=9583842&linkID=9240697
I had an issue that was causing me to crash intermittently and usually when I entered WvW or crowded places. Sometimes the crash would give me an error stating that the memory could not be written a specific address. Other times I had to kill the GW2 process in task manager. After I enabled Windows to allow programs to use more than 1.5g I have not had a single crash. I have played WvW for several hours and run all around LA. Good luck. Here are my specs.
AMD 965 B.E. stock speed.
ATI 4890
4GB Ram
Windows 7 32-bit