Yeah Mr. Amateur artist. And how are you going to prepare the CMYK files of your masterpiece for prepress with the correct color profiles as requested by your print house or publisher?What that tells me is that you are a bad designer and nobody should hire you ever. Why? Because you rely on your tools too heavily. A real designer should be able to use even Gimp for crying out loud and create good work. All of the basic tools are there.
Pixelmator has been making progress in leaps and bounds and I don't doubt that either Apple or a third party like the Pixelmator guys would step up and fill the void. I don't see this being a likely scenario but I have to laugh that you would instantly jump when your existing versions should continue to work for some time and you should not be relying on any single tool that much.
All these pretty RGB toys become utterly useless, the minute you leave the RGB color spectrum and enter the real world of CMYK and professional printing!
As a professional graphic designer I can assure you:Without help from Adobe technology NO Pixelmator art will ever get published in print!