Wind doesn't give you updates.
They come from Google and/or the phone manufacturer (depending on model - Nexii should be direct from Google)
The Canadian GN has received updates on a delay for some reason or another. If you want the latest and greatest ASAP, you can download the ROM yourself from Google the second it's available. No need to wait for OTA prompt.
CNet was reporting yesterday that Google is starting to push out 4.1 JB to Galaxy Nexus'. Makes me glad I manually flashed mine up to 4.0.4 a while back (which is actually quite easy to do) as hopefully I'll get it OTA soon instead of waiting for Samsung to push it.