So I've done a search and have not seen any word on a 64 engine upgrade for Windows for some time. Does anyone know if there are intentions of moving to the stable(ish) 64 unity engine for Windows?
The following thread is the best discussion I've seen on this forum explaining the potential benefits, or likely not, of 64-bit: https://ludeon.com/forums/index.php?topic=28546.0 . If you haven't read that thread yet then I'd certainly recommend you to as there are a lot of good posts in there (likewise for anyone thinking 64-bit would be an instant cure-all for everything and anything).
As far as I know there are currently no plans for a 64-bit version of the game (outside of the Linux version, which has been 64-bit for... a good while at least).
Thanks, I'll give it a read. Just know the additional memory would be lovely. I've had heavily modded games with no issue other than running out of memory over time :(