So how would a 64 bit operating system deal with 32 bit software? Not very well perhaps Or perhaps it runs it. If it runs it what are the advantages of the extra expense? Susapect that like much in this computery lark Whilst next weeks super processor -say- will be faster than this weeks- it will only be a bench mark thing not a real advantage - but will certainly our perform last years fastest. So consider the real advantages to you the user - not what the ads/tests say - they are after your bucks after all.
I think 32bit apps will be OK 64 bit drivers different problem - it is often hard enough to find any Vista drivers at all let alone 64bit ones 64bit allows you to have more RAM though But as you say few 64bit apps out there