My impression was that the original FRWS (remember that?) had the Puma 2 going to Afghan to replace the Merlin 3 to permit (albeit limited) marinisation before being passed to CHF. That, of course, was predicated on 22+2 new Chinooks and 30ish Puma 2. Since then the AOR in Afghan has shrunken considerably (as has the near-cash available to fund anything) and the Govt probably think they can chop Pu2 as the Merlin could go straight to CHF without marinisation if it stags on in Afg until 2015, Pu 1 will still be in the UK for any Olympic contingency role and can be quietly rolled into the long grass after the jockstrapping is all finished. Net result? Operating costs of Pu2/Pu1 saved, CHF survive (and AW will, eventually, get the job of marinising it), the Govt (much in the style of it's predecessor) will pronounce the new Chinooks (yet again) and slant them as a Puma replacement and 4 Sqns of SH aircrew will be left fighting for seats on 1 new Chinook Sqn......
What could upset this applecart? CAS digging his heels in over Merlin transfer (probably a low risk given his desire to preserve Typhoon/F35 and the RAF's post-Libya push to retain Sentinel), the AOR in Afghan expanding again or a tech problem grounding Chinook for a prolonged period (it's happened before...). Or, HMG deciding that a 100% 24/7 LitM capability is a "nice to have" rather than an 70-80% solution at a weeks notice provided by Crabair....