There has been a lot of talk recently regarding the long-term viability of Twitter and whether or not it truly belongs as one of the "social media giants" with MySpace (whose status is now debatable as well), Facebook and YouTube. Considering all of the Twitter Apps and Twitter Programs, it seems as though it has earned its rightful place.
Sure Twitter is very limited in its capabilities, because after all there's only so much you can do in 140 characters or less. But it also has an addictive quality that most of these other social media sites seem to lack.
You also need to consider the fact that Twitter is still achieving massive user growth, and has been doing such for the past 12 months. Therefore it's kind of hard to label the sites as nothing more than a passing fad.
It's not all sunshine though: the fact Twitter really doesn't appear to have much of a solid business model (do they ever plan on monetizing?) is what really concerns me and seemingly most other people about its long-term (financial) viability.
Sure, they just received tens of millions of dollars in capital, but if these investors don't start to see a return on their money, the funds will quickly dry up.
The only thing I think these investors are hoping for is some sort of IPO or complete sale of the company to some media giant or Google.
While I think Twitter certainly should stay on your radar, I'm still pretty certain it's never going to really hold people's attention the way that Facebook, YouTube and even Digg have.