If/when the 64-bit version is done, you won't need to buy a seperate version of the game. It will just install the version appropriate for your computer (so if you have a 64-bit OS, it will install the 64-bit Elemental, if you have a 32-bit OS it will install 32-bit Elemental). So you don't need to wait for the 64-bit version to be done before you buy the game.

As to if it is still being worked on, I assume it is, as I haven't heard anything to say otherwise, but I would also assume that the state of release delayed the 64-bit version.

The main  difference is that 64-bit allows you to use significantly more RAM. A 32-bit program can only use 2 GB of RAM (there are ways around this, but they're not super easy). 64-bit allows for you to use some ungodly amount of RAM. I don't know the exact number, but I think it's in the range of a couple terabytes. Windows does come in both 32 and 64-bit versions, and you need 64-bit Windows in order to use a 64-bit program. 

For pratical applications in terms of Elemental, this means you can have gigantic maps, with huge numbers of units.

Thanks you very much for the input ^^ Probably gonna go out and buy the game in the near future then, now that I know it won't be a retail all in its own.. I was thinking it would probably just be an upgrade, but with how some developers are now a days, I wouldn't be too surprised to see it sold as a separate product.  Very good to know, and makes me have a lot more faith, hehe.

No, 64bit Windows will run 32 bit applications no problem. I use Windows 7 64bit and elemental has been very stable for me since 1.06.

Thank you all for helping me understand "what it means to us." 

Basically, a 64 bit OS will allow the user to use programs that address more than 2 GIG of ram.  When this OS is installed on a PC that actually has 2+ Gig ram, the applications have the POSSIBILITY of using the extra ram. That means your application (GAMES, I'm retired, and have no use, anymore, for outlook, scheduler, etc.  LOL) can run bigger, faster, etc. (assuming the hardware, and OS is there.), IF the game itself is also designed to run 64 bit.

So the only issue that might occur is a game made for 32 bit, that doesn't take advantage of a 64 bit OS/hardware set up.I think I understand.  Thanks. 

So the concern here is whether EWoM is going to be 64 bit, or not?

It may be exabytes if it were true 64 bit addressing, but x86-64 only does 48 bit.  Windows doesn't populate the entire 48 bits either.

So realistically you've got a 16TB virtual addressing limit, and here's the hardware limits

Ability to use up to 128 GB (Windows XP/Vista), 192 GB (Windows 7), 1 TB (Windows Server 2003), or 2 TB (Windows Server 2008) of random access memory (RAM).

from http://en.wikipedia.org/wiki/X86-64

It does not matter for most people how much memory 64-bit apps can use currently, because you are most likely going to run out of harddrive space for the cache before reaching the max allowed amount.

I was just mentioning the things a typical player will notice. 64-bit allows all of that stuff too, but most of it isn't obvious. Huge-ass maps and thousands of units are the most obvious effects of having a 64-bit game.

Well sure, if you get someone else to do it for you Even still, sometimes games don't like being made Large Address Aware. For a while Impulse thought using the LAA user patch meant you were using a pirated game and wouldn't let you update. And depending on the game/company/user agreement, making the game LAA violates copyright laws, because you have to change the .exe to enable it.

I did say I didn't know the exact number, didn't I? Regardless of what the number actually it is, it's such a huge amount of memory that no personal computer will ever reach it for a very, very long time.

wouldn't 64 bit really help with insane map sizes? want insane ... with no lag... get me 64 i will get new comp then..

wouldn't mind playing with like 60+ Ai on an insane size sure other things will be balanced.. by then.

Will 64-bit Elemental also have multi-core support?

2GB by default, 4GB in an x64 OS with Large Address Aware set (which should be considerably easier than making a full on 64 bit version, but I assume they have their reasons for not doing it)