The UK job market is tough...they are only really looking for very specific skills backed by lots of experience. The recession will last for at least end 09 for sure. Too tough to predict after end 09.
Most large well known companies are really not hiring- cutting back infact. Your best bet would be with smaller companies that have won the odd deal here and there and are thus looking.
Government is also hiring with recent stimulus packages.
As for being unemployed...about 3 months is standard. You can get away with 4-5 months citing financial crisis but be sure to demonstrate what you have been doing in this time ( e.g. gone back to do an MBA, volunteered somewhere, etc).