A domain name serves two functions - to link and connect to a website,
and to provide information to potential website visitors. Whatever happens with the technology, the name conveys information concerning the content and use of the website.
A .com at the end conveys only the information that the website is on the internet. A .mobi conveys that the website is intended specifically for mobile use. With the need for short, concise names for websites increases in the mobile realm (tiny keyboards) then the value of that "mobi" information to the right of the dot - for mobile centered uses - is very real.
Those who have open minds may accept this, others will not. Never mind, there are lots of opportuntities in domaining, .mobi will rise or fall regardless of the opinions of domainers.