I don't think Apple will get rid of the mac lineup anytime soon. After all at the moment we need a mac to make apps for our iOS devices! I can't see apps being made on an iPad! Even typing this message is annoying with the onscreen keyboard!
I could potentially see them licensing OSX on non apple computers if the mac business was not profitable anymore. Doubtful though!
Also, if I think of all the people I know/ work with/ meet everyday they all still love the mac. If there is a consumer want for the mac then there will always be a professional need for a mac pro.
Mac biz is 22 billion annually according to Tim Cook. Shareholder revolt would ensue if Apple tried to walk away from that much money. Besides the Mac is growing and anyone telling you that you can be as productive on an iPad as a Mac is lying. Perhaps in certain edge cases like writing but for the most part a computer with a filesystem, automation and collaboration tools is still superior to a tablet.