When you use Stripe.js, you need only serve your page over SSL and verify that you aren't collecting credit cards through other means to be PCI compliant.
In particular, while I have no idea whether Stripe's implementation is letter-of-the-law PCI compliant, I do know that 'LeBlanc's reasoning is not PCI reasoning (particularly: you can't draw a line from architectural susceptibility to "liable to audit") --- even though it's the reasoning I myself would use.
On this link you can find the experience of Embedded payments, i implemented it on our site but the docs on the api are not complete on paypal, rather complete they are not present at one place.
I am sure everyone would agree that PCI spec is complex and not easy to understand :) Said that, its intention is pretty clear: protect credit card information from leaking to "bad" guys.
A great deal of PCI spec is about protecting the stored credit card data. You are absolutely correct that Stripe's JS solution allows one to avoid dealing with these issues. However, many other sections of PCI spec discuss other potential vectors of attacks. For example, if you don't follow security coding guidelines then an attacker can embed a malicious JS on your website (through XSS or other attacks) and steal credit cards information. Obviously, the suggestion to serve your pages from SSL don't help you to avoid these problems.
I think Stripe's model is great. But I don't believe that it allows one to completely avoid PCI compliance. I believe that you correctly phrased it on the stripe's home page: "Stripe.js lets you build your own payment forms while still avoiding most PCI requirements."
So basically: Be smart about what goes on your sensitive, mission-critical payment-receiving pages, as you should be. It's not extremely difficult. A little bit more responsibility in turn for more flexibility.
We've designed WePay solution to make it "out-of-the-box" as secure as possible for both our partners and WePay. We plan to offer more customization options in the future to improve usability while keeping it simple and secure to use. Doing security right is hard. We believe that WePay can help with it and make our partners life easier.
There's literally no security difference between processing the card transaction through your own servers, and processing it client-side via HTML/JS that your servers are providing (and can modify).
[1] I wouldn't have thought this would meet compliance requirements, but I'm not a PCI expert -- I've only had to work on compliance on the user side, and deal with the auditing requirements.
Either way, I think Stripe is doing awesome work and I hope you keep kicking ass!