This thread is reminding me a bit of the evolution of the computer.
In the 50's and 60's, computers were built on a scale where they took up half a room (and, in many case, many times bigger than that). In the 70's and early 80's, it was theorized that one day people would own their own personal computers. It took a few companies (remember IBM and Burroughs?) to make that an actuality.
It took companies after those, who decided to play with the standard box of the computer, to where you now can have a computer with a form factor of almost whatever you want, from something that looks like a small cube, to something that's an all-in-one, to something that looks like a small piece of furniture that sits by your desk.
I have no doubt that in 10 years, there may be upgrades or changes in the devlopment of e-cigs. But, like the computer, I believe there will always be a marketplace for different form factors of e-cigs.
People will like mini's, e-cig look a likes, mods, etc. There may even be a standard, but, just like the computer, there will always be a market for different form factors, each satisfying those who purchase them.
As far as mainstream, IMHO, this e-cig community IS the mainstream (IMHO) for e-cigs. All the tech here is fluid (again, just like the computer, where the tech had changed so much in the last 10 years, getting smaller, bigger, faster, and in many cases, created).
I've never worried about how I might look to the masses out there who smoke analogs (peer pressure has never been in my dictionary). It's more than enough that a community exists like this, where information and ideas can be exchanged, and where new common experiences can be shared. Pardon me if I don't wait for that perfect small-form e-cig to appear to feel like "Hey! We can be part of the mainstream now!" I'm feeling pretty good about the future of e-cigs without waiting for "Big Tobacco" to create what they feel is the end-all, be-all e-cig.