Hahah, you think snow leopard will offer an increase in performance similar to buying a new computer? One word: delusional.
I'll be happy if we get a 5% increase..
The difference in performance between an original 4-core Mac Pro and the latest and greatest is limited for everyday tasks. As you can see for yourself in Bare Feets, the raw performance increase (ignoring changes in hard drives and graphics cards) that you get by moving from the Woodcrest (first generation MP) to Harpertown (latest MP) machines is extremely limited, on the order of 10% or less. Getting that performance increase would require a new machine, which is going to be several thousand dollars.
So at that point alone, if you're right and all we get is a 5% increase in performance, the the $80 price is obviously a steal. Duh.
But...
If you think there's only 5% improvement possible in the current OS, then it's clear that you have absolutely no idea what you're talking about. OSX is, sadly, quite inefficient. Compared to similar Unix-like OS's, Linux or FreeBSD, OSX is dog slow. Educate yourself:
http://sekhon.berkeley.edu/macosx/intel.html
Much of this is due to the IPC system in the kernel, which adds overhead to everything that the OS has to do. Another dog-slow part of the OS is malloc - if they implemented a new version they could improve the performance of every machine by something on the order of 10% for absolutely no cost at all.
Moreover, most modern software on OSX is built using Cocoa, or at least the Core libraries. These libraries are NOT efficient. Minor changes to the string handling and text layout functions would have real-world impacts for every user.
The estimated performance improvements from using OpenCL, GrandCentral and LLVL are hard to guess, but are likely to b MUCH greater than 5%. Additionally, Apple is putting OSX through a serious weight-reduction process - since much of a computer's performance is determined by throughput, reducing footprint has direct impact on performance.
I think it's safe to say that if current reports of a 30% size reduction in 10.6, along with wider use of LLVL in the libraries, then you should expect a much greater improvement than 5%. But what what I know, as a professional programmer and OpenStep developer?
What I find most amusing is that when a company adds crap that no one uses to their new OS, everyone shouts that they should stop adding crap and just fix what they already have. So Apple actually does just that, and everyone's complaining that they're not adding new crap instead. As teh Steve so eloquently put it, some times you just have to ignore the users
Maury