The lesson of the last year is that dollar cost averaging works. When the market is up you contribute. When the market is down you contribute.
The other lesson is the importance of proper asset allocation. The message to the younger crowd was correct... don't lose sleep over it and just keep contributing, the market has plenty of time to come back.
The older crowd near retirement crying about the huge hit their portfolio was taking were only highlighting that they had poor asset allocation. Someone near or in retirement should have never been significantly exposed to the markets (at least with the money intended to provided that monthly income stream). Having the majority of money in the markets in or near retirement is effectively just gambling. Some tried to 'cheat' by catching up on decades of not saving by hoping for a quick win with booming markets and booming housing... those folks got burned bad--as do most people who try their hand at the craps table.
I remember a year ago there were some folks on here saying they were going to stop contributing or, even worse, pull their money out of the market. What a huge mistake. Those who stuck steadfast to their investment plans and kept investing (despite the red ink all over their monthly statement) have made an absolute killing on the money invested a year ago.
Also, your company's stock has no place in your 401k! Seriously, have we learned nothing? If you get issued shares or decent options by all means take the 'free' money... then put it in an actual diversified portfolio. Have anything more than a small percentage of your retirement nestegg in your company's stock is just asking for trouble.