Box of bricks - the only thing they were when we were kids.
Models - when we were kids models required xacto knives and volatile glue. They don't make those models any more (at least they don't sell them in Target like they used to). Lego has taken over the modeling market, and I think in net their model products are superior.
You can still buy boxes of bricks, I do frequently for my Lego obsessed son. Unfortunately, in some respects, Lego is now more a modeling company than a box of bricks company. In other respects, I've seen it argued that the transition is the only thing that has kept Lego from shutting down, so the models enable boxes of bricks to still be sold.
The Lego business was on a serious decline a decade ago (2003ish) while it was still a family run business. They knew they needed to get out of "pure" Lego and diversify (licensing, older demos) but went about it the wrong way (trying to become a lifestyle brand). What we see today is a turnaround effort by brought-in CEO Jørgen Vig Knudstorp who figured out how to help the Lego brand adapt and survive the changes in the market, one major component being all of the tie-ins to the entertainment industry. [1]
Today, we're seeing a decline in toy sales due to video games [2], something which Lego seems to be ahead of the curve on as well. I'm just glad they still produce the Technics line.
[1] http://www.economist.com/node/8083013 [2] http://kotaku.com/toys-are-dying-and-its-all-video-games-fau...