For starters profits have to be a fair bit higher than before...

For starters profits have to be a fair bit higher than before the 'crash' to get anywhere near prior EPS due to all the recent share issues.
EPS effects PE ratios which sometimes (depending on market sentiment) puts a ceiling on valuations.
Then we still have not addressed the issue of who if anyone actually pays back all the Government borrowed money to get us out of the poo. I suspect this will be done on the long term drip feed via higher taxes which will eat into consumable income which will retard growth and so on...........
This comeback is brought to you courtesy of the Gov't and not the consumer which is a LITTLE WORRY.
Anyway there are very few free dinners. I suspect this one will not be free either.
For the time being while the market points up go with it and keep stops tight - my opinion only. Gosh it looks overbought though! - but its still pointing up!