In recent years, Monarch has been switching its Luton operations from charter to scheduled, and is now left with a very small charter programme. Cosmos, its sister company is offering a greater percentage of its departures from Gatwick and Manchester, to the detriment of other departure airports.
Thomsonfly seems to market about 50% of its current flights as 'scheduled', but with its change in emphasis back to the IT market in 2008, this may reduce. Overall, 2007 saw more Tfly departures than for some years, but perhaps fewer 'charters'.
First Choice will no longer base an A320 at Luton following the TUI merger.
The XL flights are being marketed as scheduled services, and their Cyprus flights are the spiritual successor to the Helios/Ajet operation.
Since the mid 1970s when Luton dominated the charter market, the airport seems to have concentrated on changing the mix to scheduled services - very successfully it would appear. So now we have an airport that's busy year-round, not just in summer.
I personally find it surprising that, with Luton's affluent and extensive catchment area, it has lost so much charter traffic to Gatwick, which has a smaller catchment, is more expensive for airlines to use, and is less efficient.
(Before anyone shouts, my definition of 'catchment' is population within 1 hr and 2hr travelling radius - a measure in which Luton is second only to Heathrow (and perhaps now LCY, which is unsuitable for charter traffic)).