Did this workaround on Windows 7 x64 May Temporarily Be a workaround to allow you to update. Was also stuck at 0 kb/s (NorthEast US)
1. Close the GW2 Launcher
2. Open Notepad (Run as ADMINISTRATOR)
3. Edit C:\Windows\System32\Drivers\etc\hosts using notepad (run as administrator)
4. Add this line at the bottom:
174.35.56.164 assetcdn.101.arenanetworks.com
5. Save the file. (If Notepad prompts you to save it as a new file, you need to start over and run Notepad as administrator.)
6. Run GW2 Launcher
If this still doesn’t help, you may need to change the address above and try a different number (e.g. assetcdn.102.etc..).
Later if the issue is resolved you can simply re-delete the line from the hosts file.
Hope this helps, worked for me.
(edited by trlent.9607)