Generator Research, a small firm focused on digital media and the Internet, has released a new report predicting that the Apple iPhone’s current growth trajectory will enable it to catch and surpass Nokia for the top spot in the global smartphone market within three years.

The report sees iPhone growth accelerating due to a combination of the rapid multiplication of apps and the price drop of $99 for the lowest-priced iPhone. Meanwhile, Generator Research also predicts that Nokia will stumble and see its market share cut in half from 40% in 2008 to just 20% in 2013.

Chart credit: Electronista

Quick analysis

This report appears to compare Apple and Nokia in a vacuum. It sees only modest growth for other smartphones in the years ahead. That doesn’t take into account the momentum that both BlackBerry and Palm also have right now. I think we have to expect that as the smartphone market grows steeply over the next several years, it’s going to lift several boats, not just the iPhone.

As the smartphone market grows and consolidates, Nokia is definitely vulnerable, as is Windows Mobile. Google’s Android platform is still a wildcard. It has potential, but also has some serious challenges to overcome.

However, this market is still extremely fluid. Nokia has yet to launch its new Symbian OS. Windows Mobile 7.0 comes out in early 2010. And there’s still the possibility that Android could find the right hardware partner and turn its fortunes around.

If there’s anything that could give the iPhone to leap forward in the global market, it could be partnerships with new mobile carriers. For example, if the iPhone comes to Verizon in the U.S. in late 2010 (as rumored), it could have a very disruptive impact on that market.