I agree that valuations are abnormally high (although not higher than those during the dotcom bubble) and that a correction is due soon however, this time really is different in the sense that the damage will be largely contained to those with enough money to throw down on startups (VC/PE funds, institutional investors). For better or worse, tech startups are staying private longer, holding private IPOs and generally staying away from the scrutiny of the public market while at the same time insulating the general public from a crash.
What will largely suck will be the uptick in unemployment not just from failed and failing startups having to lay off employees cause of lack of funding, but the associated kill-off of the entire services-for-startups industry. Did I mention the lack of funding? That'll also suck for newcomers who came at the wrong time.