I want to get into this thing. I think that bitcoin has quite a few flaws and that some other currencies address a few of those flaws. Is bitcoin too popular to be overtaken? Is there room for multiple coins to have value (in the long run)? I imagine most of the established ones will stay around in some form or another, but will any alt coins ever become mainstream?

I guess this is a loaded question, but I'd like to hear some perspectives. I'm thinking an alt coin is a better gamble because it would have larger growth opportunities, but bitcoin might still give a really good ROI.