Stating the obvious, but lack of locational stability and diminishing flying jobs post +10 years are the biggest factors. Certainly the 17K/20K has made the gap to the LCC's bigger.
I'm going to guess that the legacy carriers are still going to be too attractive when they start recruiting again.
With this Aircrew Capability Allowance being up for renewal/extension in Oct 2011 the next iteration will miss the departures in late 2010/early 2011. I reckon they should've gone with annual renewals to remain more responsive.
How much higher will they go in Oct 2011 that's the question??