As I'm impatient I emailed Pacesetter last week to see if they would tell me when the registration would open, and got this back today:
Entries for 2011 are planned to be open some time in December, 2010. If you are registered on the site for the newsletter and on our twitter page we will announce the opening of entries the moment we go live so just keep an eye out.
We had intended to open registration at the end of October but following a small number of complaints from the public re the behaviour of a number of cyclists on the Vitruvian course in September 2010 we are now in a position where we are required to undertake additional discussions with the relevant
authorities in order to investigate more fully these allegations and find solutions where necessary to ensure the safety of all competitors and the public during the staging of the events.
Once again we apologise for the delay in opening the registration and whilst we do not envisage any major problems re the staging of the events in 2011 we feel it vital that these issues be fully addressed before we are in a position to open registration.
Dates for next years diary remain as previously announced
VITRUVIAN TRIATHLON saturday 3 September 2011
No idea what the complaints are (although a mate of mine was one of the bike marshalls this year so I may contact him and see if he knows), but I hope they're not so serious it buggers the event up. 
Guess I'll just have to be patient a bit longer too!