im having the same problem where i can start up the game but then i just get a blackscreen with the cursor of gw2 (somtimes even without)
but it just freezes there. when i go to the taskmanager it says that the game is not responding. ive had this problem since the big patch where they implemented the frost and flame thing with the refugies. also my modem is directly in connection with my pc so its not a good fix either :S.
Ive send arena net a mail explaining my issues i hope to get a respond soon if it is fixed for me il call it in on this thread and you can enjoy youre gw2 time