Hi...want to get Thunderbolt display and a mac laptop...like idea of having a desktop and a laptop if need be (though mostly will use as desktop replacement) . Seems like current MBA can handle the display fine...but is it "safer" to get MBP with the discrete Video card?....I really just do basic stuff on the computer...dont game, but wonder if MBA Intel graphics will get so outdated over next 3-4 years...my usual replacement cycle. thanks