I would be excited to see the iPhone 5 in 32/64 flavours, not because I need a 32GB iPhone, but because it would mean the iPad 3 would come in 32/64/128. Then I could go back to the lowest priced iPad.
However, I doubt this will happen. I think 16GB is more than enough for most people and if Apple had 32GB for the base memory of both the iPhone 5 and iPad 3 then they would lose a lot of money from people who otherwise would have paid $100 because 16GB isn't enough.
You are mistakenly assuming that a 64 GB iPhone means their base model would be 32 GB. If anything they would transition to 3 GB offerings (like an iTouch and iPad). Whether that would be 8/32/64 (iTouch) or 16/32/64 (iPad) remains to be seen. My guess is 16/32/64 this fall for the iPhone 5.