A few things to throw out there..

1. When you go to whoisredjohn.com it says 502 Bad Gateway or 504 Gateway Time-Out
2. Red John is "Bad"
3. Gateway backwards is "ya we tag"
4.  Ya "we" meaning him and his alias are "tag" Tagliaferro?
5. 504-502=2 so there might be 2 people not on the list coming in next episode and one of them is Red John...
6. "Time-Out" Obviously Red John (aka:Gateway) time has run out.

IDK but it looks like we are getting close.