Here are a few comments/points and a wall of text from an 10.6 user:
Apple seems to have gone off its nut with respect to OS support. They need to think of supporting their users in terms of years, not OS versions. Five plus years should be a minimum. If your hardware can hang in there, then so should your OS and other software!
I have an almost 4 year old MacBookPro, which can technically be upgraded to 10.7, but when I did so, the fans were running full speed to keep my machine from melting ;^) (fine so I use an external fan even with 10.6 and SC2), but my comp ran too feebly with 10.7 so I downgraded back to 10.6 (Ahh! sweet stable dependable 10.6 :D).
With respect to those who argue, "Just spend the $20 bucks, silly!" It's the buying a new computer that's required to support the new OS's that's the issue! And that price tag is a tad north of $20. Then like others have said your legacy software world dies. Yes, we all have to face this sooner or later and move on, but Apple's recently accelerated fast OS turnaround, and slamming the door on 10.6 users was dramatic and harsh. WAY too sooner; should have been MUCH later. I can't even begin to describe how much of my software has been orphaned. Apple has become so cool it's cold, and that kind of bitter cold, bites.
Take elementary school computer labs (using Macs) for instance: Most schools/districts budgets are strained to keep their labs up and running; it takes considerably more than five years to gradually upgrade a lab – buying a handful (at best) of new computers every year, which they can barely afford. My friend's kid's school has computers that will be over 12 years old before they can replace all 30 Macs. If you include their classroom macs and teacher laptops, they have OS 10.3, 10.4, 10.5. 10.6, 10.8, and a 10.7 server! Plus, the costs of replacing legacy software are huge, and there's the curriculum that's been developed along with the legacy software that needs to be retooled. Not to mention the ramped up technical support and lost time due to keeping unsupported Apple investments up and running. It must be costing U.S. schools hundred's of millions of dollars to attempt to retool, but it's become a fools errand. Schools will never be able to keep up with a 2-3 OS/year turnaround; they simply don't have the money. Apple's short support window amounts to dropping Apple's commitment to Education – at least desktop/laptop wise. They want them all on iPads I guess, but what's their useful life?
What does this have to do with our beloved Blizzard/Starcraft? Apple's been drinking their own Kool Aid (made super sweet from iOS sales and sitting on billions in cash) for so long that they've lost perspective. There's going to be some desktop/laptop market blowback coming for sure. I used to feel the love, now I'm feeling something else; like a long time friend has died.
Blizzard should be looking with a cautious eye at Apple's foley, and do their best to take the long view. Think of the economics of the average Joe, and not the marketing and support policies of the shiny Apple with their new and improved bitter taste. Do your best to be the beacon :^) and support the older operating systems, because the average woebegone Apple Joe needs you to.
I've been a blizzard fan since SC1 & Warcraft 1 (remember the ships?!) I still play SC1 on my 2004 Laptop once in awhile; and it's so cool that I can do that!
Lastly, and with respect, I wish Blizzard never went to a client based model. I want my disk and hard drive based app, and I miss my bright and crisp pre 1.5 patch graphics and look and feel to SC2, but I digress.
It's good to know that I have more than 4 weeks left to play my favorite video game of all time, SC2, because I won't be able to afford a new computer any time soon; and that may be my first PC.
GG to all!