Whilst I don't doubt there is a good deal of ageism around in all industries, especially one that is still relatively young itself, I have been very fortunate in being able to avoid it.
I have just turned 52, still a code monkey first and foremost and thrive on keeping up with the latest and greatest technologies. It's what I get out of bed for and hope to be able to do so right up to retirement age. What I suspect (in truth, know) I am loosing in mental sharpness I would like to think I more than make up for in terms of experience, perspective and general worldly wisdom.