In the good old days you needed two or three pairs of skis, depending on how serious you wanted to be on the race course. You would either tilt GS or Slalom, and ride those as your go-to board, and then typically you'd keep an old pair as rock skis for the early season, and those rock skis usually doubled as your powder skis, because they'd soften up over time and get sweeter in the deep.
As I say, racers would need dedicated GS/SL planks, but most of us could get by picking one or the other depending on taste (myself, I was fond of GS skis). And then came the great shaped-ski revolution, and the rise of the All Mountain ski, and for a time one ski was really all you needed (racers, once again, excluded). Skis like Atomic's 10:20 added both shape and width underfoot, carving like nothing we'd seen on hardpack and floating like a dream (or so we thought) on fresh.
Shaped skis were so good—and so much better than their predecessors—that many of us simply tuned out on all subsequent ski advances. It was as if ski design had reached its pinnacle, and there was no reason to ever worry about trying anything else. You can see evidence of this even today: many riders simply refuse to abandon that generation of ski, which remains fairly ubiquitous in lift lines across the country.
And now we have the rocker revolution, which I suspect will prove every bit as consequential an innovation as shaped skis. Rocker, like shaped skis, arrived with many false starts, but we are seeing the technology mature, and the results are inarguable. The sport has been transformed by it. Rocker positively annihilates the concept of the one-ski-quiver, creating instead narrow niches of specialization. While individual skis can and do perform across a spectrum of conditions, it is when you hit that perfect combination of snow and ski that the magic truly happens.
Like a surgeon selecting a scalpel, today's skiers are rewarded for a nearly-clinical obsession with getting the right ski underfoot at the right moment. The payoff is positively other-wordly: experiencing skiing as it previously existed only in dreams.
But where does this level of specialization leave us?
For starters, I would argue that it is time to pass the torch on your old planks. Faithful years of loving service they gave us, but their day is done. Truly. Skip entirely the prologue phase of rocker, and start demoing skis of either this or last year. You will likely find you can't live without at least one rockered powder ski, and you might find yourself sorely tempted to pick up a rockered All Mountain ski as well. As for carving on hard snow, here the news is kind of grim.
Rocker naturally inspires a different kind of skiing, even a different mindset. Perhaps, outside of racing, carving exquisite turns on hard snow will become a lost art. In any case, it remains an art that demands a cambered (read: old-fashioned) ski. So add another ski to your growing quiver, if elite-level carving is among your requirements. (And even here, Rocker is making inroads, thanks to innovations such as so-called 'adaptive' geometry)
The bottom line is that skis and indeed skiing have changed. Don't let an innovation of the past (shaped skis) prevent you from trying the innovation that is transforming the sport today (rocker). Get out there this winter and demo some of the new skis. They really are that good.