I don't quite follow HZ123s comments regarding "lack of stand facilities, fuel provision, equipment, safety equipment, restricted/controlled zone and general security." as being major problems. Perhaps he can elaborate.
Included in the planning application is provision for a new airside security fence and surely there is no problem with stand capacity nor refuelling (OK, not hydrant, but that hardly matters surely?). SEN's geographical position has also always been held as advantageous with regard to Airway access and standard arrival and departure procedures are already in place aren't they?
I certainly cannot understand why RAL failed to issue a Press Release or to answer the Evening Echo's enquiries (the paper having reported the planning application as a very positive move). Perhaps RAL didn't realise the news would come out so quickly, which was pretty naive of them if so.
As far as the extension being "a botch up", I doubt that the application would be approved if that were so and I can see no reason why the resulting modified terminal should not be user-friendly and perfectly acceptable to potential airline customers. I shiny new terminal doesn't ensure lots of business anyway - been to Caen recently? Nice terminal -shame about the almost total lack of traffic. What's important to potential airlines is the large catchment area that SEN possesses, as well as having the caché of being 'London Southend', and providing the terminal ensures efficient, pleasant processing of the pax to ensure rapid turnrounds I cannot see an airline complaining that the terminal isn't a marble-halled palace.
The loss of the railway station (if the new terminal has been put on ice) is a drawback but perhaps the bus shuttle to Rochford station could be reinstated.
As Southender suggests, it certainly looks as if there has been sufficient airline interest to warrant this move so let's hope it leads to some route announcements in the next few months.