They are the 4 pros from london sponsored by prima poker.
I am currently 7th in their site league and have won 3 of their card protectors ;]
They aren't playing in every event due to the structure, if they have done well in an event and have to play in day 2, they will have to skip the event that starts that day. So far though there has been at least 2 of them in every event thats open to the public. Also gotten a fair few cashes between them as well already.