I found it. They haven't put it up on the UK census collection section yet but if you do a search on all the censuses at once, there's an option to select only the 1841 census. I almost always search by clicking on whichever census I'm looking for like 1871, then search on the 1861 etc. I don't tend to use the other search facility which is why I didn't find it initially.
Thanks millerina (my mum will go crazy when she gets back today to find out it's been released!)
Andrew