Looks very healthy from here. I think the way was led by several major retailers. We’re seeing significant migrations from oscommerce, various hosted cart products and others.
Well, I can’t speak for other’s but the increase in enquiries has been hard to manage. Magento isn’t something that a developer can learn in a couple of days or a week and so the main issue is getting good people right now.
I think Magento’s taken off worldwide, not just the US or Australia.
if you take a look at most of the web developers they all have an “ecommerce” option and about 50% seem to list Magento as their choice.
I just built one new Magento store and have an old OSC store which needs a serious overhaul and may go to Magento as well (though I am considering BigCommerce as it’s also making huge waves.)