Based upon Apple's published financials, the iPhone now represents approximately 40% of company's revenue. But what is just as impressive, is how Apple has fared through the recession.
Think about this, the iPhone is only about 3 years old as a product and has a limited distribution channel in the US [even though it can be jail broken and untethered from AT&T - it operates with limited functionality].
When Apple launched the iPhone there were many debates as to how well they would do and if it would be a success. Apple was looking at capturing 1% of the smart phone market - and they believed if they could, then they would be a success. Now, they are 300 pound gorilla in the market [along with HTC - another relative new comer] and have basically pushed Nokia and Motorola out of the way during their climb.
It will be interesting to see what happens to their product line over the next 12 to 18 months - with the introduction of the iPad, the functionality of the iPod Touch, along with new laptops - and how will the product mix change during that time.
Also visit Walt Casey's blog - http://iphoneperspectives.blogspot.com/