Do helmets go out of style and get discontinued by manufacturers? Issue: 
My head is on the smaller side, so all "universal adult" helmets don't fit me. I've been to a couple LBS's recently and tried on just about all their helmets, from most of the popular brands (excepting Specialized). Most Small sized helmets I tried on don't even fit very well, some of them are in fact too tight. Going into winter, I decided to go for a cheaper, warmer helmet. However, I am pretty sure next summer I will not be able to handle miles and miles in it. I have found two other helmets (with lots of venting) that I would say actually fit comfortably (my primary criterion), one in particular I really like the look too.

Question: should I pick that other helmet up now (Bell Sequence) just in case it gets discontinued? I won't be wearing it for quite a few months, so it's kinda silly when you're on a tight budget to buy something before you need it, but I sure do like the fit (and venting).
In most bike shops, if they have a helmet in stock, they will sell it even if it's last year's model, rather than ship it off to a remainder seller or some such.  But, of course, if they sell the helmet, and the model changes next year, they will not get more of the old ones.

I would guess that helmet manufacturers turn over their product line about every three years, doing a little bit each year.  There's no good way to know if this year's model will be around next year -- it might or it might not.

So you figure the odds.