There is a business case that can be made for Apple moving to PCs. On the simplest level, Apple could become the Sony or Bang and Olofsen of the PC market. But the point is that if Apple can get their parts easier, get to the cutting edge sooner, and has more suppliers, the company can improve their supply chain (parts and manufacturing channels). Apple would be an instant and significant player in the PC market. Some people would buy x86 hardware to run Windows or Linux on. Some might run MacOS X on other PC's if they could. Certainly a few business cases could be made.Read more at osViews
However we're still not sure whether Apple will announce a move to Intel chips on Monday. Everything you read on the internet right now is just rumour and speculation, it could well even be just a joke

For instance some sources say it might be that this isn't about processors but about other technologies such as WiMAX, a broadband wireless technology, which is going to be heavily promoted by Intel. Others say Apple won't solely use Intel chips but might also use AMD for some models and their is still doubt whether this is about x86 processors or not.
Everyone is now anxious to know which of all the 'Apple to go Intel' rumours are true, but we'll have to wait until the Apple Worldwide Developer Conference on Monday to know more about it.