Hello Just,
I won't deny that for certain people 32-bit systems are still perfectly useful. Just my clients do not share this view for a series of good reasons. Even their older systems tend to be 64-bit nowadays. Migration towards 64-bit OSes is under way. There is still 32-bit compatibility if needed. At the same time certain programs will perform drastically better when compiled to 64-bit. Replacement thus can be postponed which is usually the best way to keep CFOs happy.
If you know in advance that ALL of your market is 64bit today, or If you expect the client to buy whatever you tell them to (I understand that graphical designers buy whatever the photoshop box says to buy) that's one thing, but If you are selling to people who will only upgrade if forced to, then only shipping in 64bit is just spending someone else money (never a good idea). It sounds like you might be in the first cases so you might be fine, but enough users of D are in the second case that 32 is not a waist of time for a lot of people.
