Charlie,
Sedo emailed me back to say this applies to UK "Customers" and not UK (.co.uk) "Domains". So the £100 minimum still applies.
They claim the transfer process is difficult and time consuming hence the cost. Well in our experience it is just filling out a few forms.
So when they say:
"NO MINIMUM COMMISSION ON DOMAINS PARKED WITH SEDO! – NOW FOR ALL US / UK / INTERNATIONAL CUSTOMERS!" and "no more minimum commission on almost all parked domains"
err well no actually it doesn't apply to ANY of my domains as a lot of UK customers like myself will have nothing but .co.uk domains!