The Luton base is closing, thats the reason for LTN - IOM closing. Last flight is today i think. All the crew are relocating to Ireland. Aer Arann don't have any IOM based a/c but do have engineers and crew here for the ATR 72 they lease to Eueomanx and to sort any problems with their own DUB - IOM flights.
The above post was saying 2007 is the 100th anniversary of the TT races and so loads of tourists willl be trying to get to IOM during May and June. Rock the Rock is a music festival, apparantly expecting 35,000 ppl.
So with only LCY and LGW fares will be high. Most ppl travel by boat for those events though
Hope that helps you