It is time to reduce the carbon emissions

Last time I wrote here I was still a member of the QA team and I was announcing the launch of the qt-stable branch. Well, after two very successful years on the QA department I decided to change directions and I joined the platform team working on the Mac platform.
So, one of my first tasks required me to investigate a bug in full screen mode which only affected Cocoa applications. This led me to dig into the code and find some things that needed to be improved. While looking at that, I remembered that when developing the Cocoa port we reused as much code as it was possible from the original carbon port. This saved us a lot of time, however as time passed both ports started diverging and now the code has grown a little bit "confusing". So, I started looking at the way of separating both ports completely and create completely different code paths for both of them. The more I looked at it, the more I realized that the task was not a small one and it would take quite a lot of work. Then I asked myself, why do we need to keep the Carbon port? After all, Carbon is the past in OS X and it has been completely replaced by the Cocoa framework. I talked to my manager, who told me this had been an ongoing discussion for a while, and the main reason for the Carbon port to exist is to support customers deploying applications in OS X 10.4 aka "Tiger". Cocoa is available from OS X 10.5 (aka "Leopard"), before that the only available framework is Carbon. Doing some research on the Internet we found out that OS X 10.4 hasn't been updated for about two years, and it seems very unlikely that Apple will release a new update after the last released version 10.4.11 (2 years ago).
Since we are aware that for some people Tiger support might be very important, we are reaching to you to find out the reasons why support for Tiger and/or Carbon are important to you. Could you please let us know the reasons this port and Tiger support are vital to you?
In case you are wondering, no decision has been taken yet so this is the time when you can influence the future.