While I wouldn't expect BA's announcement to affect the current round of DEP or CEP recruiting, I wouldn't be surprised to see the targets for next year and beyond being reduced.
BA in particular have been hit by the double whammy of the downturn on the Atlantic and the low-cost carriers in Europe. Just at the time BA's policy of concentrating on the high-yield business and first class passengers was coming to fruition, the corporate travel departments are shifting their contracts to economy, or using the phone more! This is going to be tight for some time for BA - don't expect their much-trumpeted pilot pay dispute to achieve a great deal, either.
Britannia has also announced some job losses, I believe, and I wouldn't be surprised to see most airlines quietly adopting a no-replacement line to allow the people count and wage bill to reduce.
Watch Flight to see what's happening with aircraft orders and leases to get a feel for the pilot market in the nearish future. If you see orders being deferred or converted to smaller types, options not taken up, and older types being retired early, you'll know the accountants are getting uncomfortable. That will, in turn, have an effect on the pilot recruiting numbers. Make sure you have a back-up plan!