I HAVE DONE IT :)
Yes, I have managed to write 50 000 words in a month (51, 490 to be precise!)
I am going to save it in lots of places and leave it for a while before coming back to read through and edit. I plan to put some extracts on my blog - would be really interested in feedback.
The whole point was to see if I could write that much and try to tie it into a coherent story. I have never written this much before and am really pleased that I did it :O)