The retail folks I speak to all love Apple, while people who manage money for a living either love it or are dying to short it but are too scared. I see both sides of the argument as in many ways it encapsulates the entire market. The bulls will argue that the valuation is reasonable, while the bears will argue that the earnings are not sustainable in the long run and that it has gone too far too fast.
If I were going to short Apple I would wait until late April. In the coming month a lot of money will be entering the market. The pension/IRA/401K contribution deadlines are rolling around and tax refunds often get put into the market as well. A large chunk of this money is likely to find its way into Apple as it is the most loved stock out there. I would wait until everybody gets in before trying to short it. Its possible that it will pull back before then or even top out. But the best risk/reward on the short side would be if it is still soaring in late April. By the same token I would be very careful with longs at that point.