Is Apple (AAPL) a bubble waiting to burst?

It's interesting following the iPhone and iPod company Aaple recently especially with the recent valuation that places it slightly North of $700Billion. This makes it the world's most valuable company in terms of market capitalization. Now, I am an Aaple enthusiast and buy into their philosophy of making long lasting quality products. The shares of Aaple closed at around $124 today and both the Bulls and the Bears have their cases as to why this valuation of the stock price is either too conservative or hugely inflated. One of Aaple's biggest shareholder Carl Icahn and his fund seems to think that shares of Aaple should be trading somewhere North of $226 per share giving Aaple a valuation of around $1 Trillion which would make the company's worth similar to the GDP of South Korea. Interesting to say the least. Question remains, is Carl Icahn right? Or is Aaple's stock just a bubble waiting to pop?