The reality of the situation is a little more complex though. When you start with the desktop platform, you tend want to take advantage of everything that platform has to offer. You build an amazing product that leverages lots of great technology, only to realize that none of it scales well down to mobile. This can and does lead to severely watered down mobile products that feel more like an afterthought than a polished, finished product. Does this happen with every project? Perhaps not, but the story is likely far more common than you’d like to believe.

"The site works as expected without JavaScript" Yeah baby

The Mobile Case for Progressive Enhancement

Re @codepo8 's new article There's also the JS "semi-available" case in Opera Mini:

Progressive enhancement with the traditional three tiers of HTML + CSS + JS misses something. Tier 0 is the Server.

"JavaScript and the end of progressive enhancement" by @skilldrick My own position on this is still "it depends."

via Daring Fireball