Should I get the Lumia 800 now?

Hello all.

I know the Lumia 920 will be coming out soon, but I don't know if I can afford it. There are now some pretty good deals for the Lumia 800 or Lumia 900 around right now. What do you think, will I be missing out a lot since they wont get WP 8, or will it bring mostly changes that the 800 and 900 could not support anyway? Also could someone comment on the battery life of the two?

Thanks a lot for your advice!