I was very excited to read last week that the upcoming release of ColdFusion 9 Standard will offer 64-bit support (currently with CF 8.01 you must purchase CF Enterprise in order to get 64-bit support).
I have many medium to large-scale client websites that consistently run out of RAM (a common problem with sophisticated CF frameworks and their successful caching implementations). However, none of the sites have required (nor have purchased) CF Enterprise.
The thing is, when it comes to hardware on a server RAM is cheap (unless you're using something like a paid VPS solution - somehow most of these hosting solutions get away with charging you more per month than it cost them to purchase the RAM on the server for a one-time fee).
Currently the RAM limitation in CF Standard (32-bit) is approximately 2GB (a limitation having to do with 32-bit java). However, "the emergence of the 64-bit architecture effectively increases the memory ceiling to 264 addresses, equivalent to approximately 17.2 billion gigabytes, 16.8 million terabytes, or 16 exabytes of RAM" (Wikipedia).