While I realize that what politicians say before they are elected and what they actually do after they are elected are very different things, reading
BBC News - Ed Miliband: We'll tackle deficit with 'sensible' cuts
implies that if Labour are in power/coalition post 2015 then
every government department except the NHS (and you can expect Education to eventually be added) will face budget cuts year on year until the annual deficit is reduced.
All parties are falling over themselves to state how they will reduce the deficit, against this background I can't see how SDSR 2015 will be anything other than another capability, for which read cost, cutting exercise.
Funding for new assets (such as MPA/MMA) is likely only to be feasible if something else is given up. Depressing times for the military as asset after asset, base after base and capability after capability disappears.
Oh, government sector workers can also expect minimal pay rises for years to come, which the government of the day will justify on the basis that inflation is currently only 1.2%.