CS4 Photoshop and Snown Leopard 64 bit

Question

Up to this time we had a cap of 4gb of ram we could use for Photoshop and other programs because of 32 bits. Now that Snow Leopard is coming out this Friday, will Photoshop CS4 on Macs be able to take advantage of the 64 bits AND take the 4gb cap off and allow us to use the availible ram we have? I run on a new Mac Pro 2.26Mhz 8 core processor with 12mbs of ram. What I've read is that this should speed up the whole work flow.

Answer 1

Adobe made the announcement that CS5 will be 64bit.
Here is why CS4 is not 64bit. Basically Apple changed the rules at the last minute.
From John Nacks Blog. 4-2-08
As we wrapped up Photoshop CS3, our plan was to ship 64-bit versions of the next version of Photoshop for both Mac and Windows.  On the Mac Photoshop (like the rest of the Creative Suite, not to mention applications like Apple's Final Cut Pro and iTunes) relies on Apple's Carbon technology. Apple's OS team was busyenabling a 64-bit version of Carbon, a prerequisite for letting Carbon-based apps run 64-bit-native.
At the WWDC show last June, however, Adobe & other developers learned that Apple had decided to stop their Carbon 64 efforts. This means that 64-bit Mac apps need to be written to use Cocoa (as Lightroom is) instead of Carbon. This means that we'll need to rewrite large parts of Photoshop and its plug-ins (potentially affecting over a million lines of code) to move it from Carbon to Cocoa.
Now let me be very clear about something: It's entirely Apple's call about what's best for the Mac OS and how to spend their engineering cycles. Like any development team, they have finite resources & need to spend them judiciously. They've decided that Carbon 64 doesn't belong on their roadmap, and we respect their decision. It's up to Adobe to adapt to the new plan.
As soon as we got the news in June, we began adjusting our product development plans. No one has ever ported an application the size of Photoshop from Carbon to Cocoa (as I mentioned earlier, after 9 years as an Apple product Final Cut Pro remains Carbon-based), so we're dealing with unknown territory. We began training our engineers to rewrite code in Objective C (instead of C++), and they began prototyping select areas to get a better view of the overall effort.
In short, Adobe has been taking prompt, pragmatic steps to enable 64-bit Photoshop as quickly as possible on both Mac and Windows. It's a great feature, not a magic bullet, and we're delivering the functionality as quickly as each platform permits.
http://blogs.adobe.com/jnack/2008/04/photoshop_lr_64.html