Apple absolutely is in a bubble - not just their stock, but their consumer products as well. That said ALL consumer electronics are in a bubble as well.
You look at the input costs of material and labour for a typical consumer electronic and look at the retail price, I'd say you're looking at least a 300-400% mark up. I'd bet it doesn't cost more than $100 - $150 to bring an tablet computer that retails for $400 - $600 to market.
10 years from now, I'd bet 90% of the tablets and smartphones manufactured today will end up in landfills or garage sales, where they will be resold for a fraction of their original retail price. The reason? The material costs of the devices is so low and built in obsolescence with consumer electronics is probably the worst of any manufacturing industry. I bet you the INTRINSIC VALUES of most consumer electronics (that is, the aggregate market price of all the components it is comprised of) are a fraction of their original purchase price.
The only reason people value said electronics is because of the perceived utility and novelty of them. The problem is, most of the utility and all of the novelty of these devices is grossly disproportionate to the price a consumer has to pay for what they get, and the profitability of Apple especially will most certainly serve as an indicator to other producers to get their act together to flood the market with equivalent products cheaper. As it stands now, it costs a week to a month's salary to buy a smartphone or a tablet.
Think about it - when the land line telephone was developed, it was a revolutionary technology and I'm there where a lot of idiot "early adopters" who paid a week's to a month's salary for a landline phone. 150 years later, you can get such a phone for under $5 (less than 1 hours worth of labour). Desktop computers were worse as and the speed at which it went from being 1 months salary to get a crappy PC to a few hours salary to buy a vastly superior one was only a matter of years.
I believe it will be a measure of months at which the affordability of smartphone/tablet computers/etc. hits a similar phenomenon. When that happens, I think Apple especially will fall like a rock both in terms of their share price and the price for their products. That's assuming things keep stumbling along and there is no major economic down turn. If there is a huge economic downturn, I'd expect the consumer electronics collectively to fall through the floor as people enter survival mode and because you can't eat an iPhone.
Just look at RIM:
http://www.google.com/finance?q=RIM
They went from $148 in 2008 to $12 today (down 91%), all because there management team made just a handful of really stupid decisions and a competitor came out and blew them out of the water. They're tablet price went from $500 to $200 in under a year (I like my Playbook, but I still think I overpaid to get it for $180).
Is Apple immune from the same fate? Absolutely not.
Could Apple shares be worth $54 (down 91%) a few years from now (or sooner) - you bet. In perspective, in the same time could silver be worth $2.7/oz (down 91%) - possibly as well. Which of the two do you think is more likely though?
I'd stick with silver, myself.
Their earnings report comes out on Tuesday so that should be interesting. I would guess with the release of the Ipad3, they may not dissapoint. Stay tuned!