So you're an East Coast rider, at home on icy trails and hard-packed terrain parks. You've been 'West' for the goods every so often and you have found that the short, soft freestyle deck that served you so well on the local mountains isn't cutting it in the Utah pow and Northwest steeps. Now you're thinking you need a powder stick, or at least something longer to help with all the leg burn that's bringing your fun to a standstill.
Where to start? Well, ask yourself this: what is your riding style like? Are you more interested in blazing through the deep stuff as fast as you can? Or would you rather play around on natural features: dropping spins, buttering powder, riding switch, et cetera? Maybe you just want to cruise and link some beautiful powder turns. You should ask yourself this because a pure powder board is not easy to justify. For the average salaryman/woman who rides primarily on weekends, you might get a decent amount of snow a few times a season. Once or twice every two or three years, you might see a dump of epic proportions. Add it up, and you might be riding a powder-specific board about five days a season. I hope you catch my drift.

The purpose-built deep powder deck is the swallowtail, or more recently, the fish. These boards split right behind the rear binding and have long, wide, pointy noses to help keep you on top of the snow. Leg burn is a thing of the past when you're sailing through the fluff on one of these. They are meant to be ridden fast and will generally turn on a dime. However, don't even think about riding or landing switch on one of these. One benefit is that, in deep powder, the board will 'fix' your landing by planing itself, so you can ride away smooth. Boards like these are probably well-suited to backcountry riders searching for bottomless snow, those who refuse to get stuck in the deeps, and high-velocity freeride jocks. A few examples: Burton Fish, Nitro Gun, Nitro Slash 171, Rome Notch 162 & 172, Rossignol Big Gun, Rossignol Half Gun, Winterstick Swallowtail, etc.
One step closer to practicality and versatility is the taper-tail or pin-tail snowboard. These are shaped more like your everyday snowboard except that the tail is narrower than the nose, which induces float by burying the tail and bringing up the nose. For the most part, they ride like a regular board, too. Take these guys in powder, on groomers, in trees, and almost anywhere else. They will even take a switch stance in a pinch, so long as it's not in a lot of powder. Some taper-tails include: Arbor Abacus, Burton Malolo, Burton Supermodel/X, Lib Tech Snow Mullet, Neversummer Summit, Nitro Pantera LX, Rome Notch, etc.
For the freestyle-minded rider looking for a freeride deck, there are simply a ton of medium to stiff flexing twins, directional twins, directionals to choose from: just pick a bigger size. These are the best if you've got some spins you want to throw into powder and not have to worry about landing switch. These are boards you would normally ride on groomers and just about everywhere else. Of course, you will still have to set the bindings back a bit and lean back, but that's the price paid. Boards in this realm are numerous: Arbor A-Frame, Arbor Element, Bataleon The Enemy, Burton T6, Burton Custom X, Lib Tech Phoenix, Neversummer Premier F1, Nitro Blacklight, Nitro Misfit, Ride Concept UL, Rome Anthem, Rome Design, the options are almost endless.
Then there is the issue of rocker. Some people like it, some people don't. I am not yet a convert, but I will say that it does make a big difference in pow: just lifting your front leg is enough to get you over and floating. It's worth trying.
As far as women's boards are concerned, there are precious few in the way of women's swallowtail boards. The Burton Fish is available in a 150cm, 156cm, and 160cm, supposedly for women. A little more luck is had with tapers: Burton Malolo in 149cm and up; Burton Women's Supermodel in 146cm, 151cm, and 156cm; Rome Notch in 155cm; and Salomon Women's Sick Stick in 153cm and 156cm. I guess you gotta hand it to Burton for really taking care of the ladies. Hopefully, more companies will get on this and supply women-specific powder decks.
Personally speaking, I rode an Arbor Wasteland 155cm (directional twin, mid-wide) in the powder of my life (100 inches in one week in Utah) and it was okay. There were moments when I thought I could use a bit more length, and I definitely tomahawked a few times, so I picked up a Nitro Blacklight 157cm (directional twin, mid-wide) that I haven't tried out as of yet. Homegirl is enjoying her Arbor Push 148cm (women's directional) and Roxy Envi 147cm (women's directional twin) in the pow, but you'll have to ask her about her thoughts.
Final thoughts: a longer-than-usual deck will probably suffice for 90% of your deep-snow needs, but when Mother Nature is puking up champange powder, I always wonder if I should've dropped the cash on an Arbor Abacus or something. If you ever find yourself on a heli-trip, a $500 swallowtail or tapered board will probably be the least of your expenses.
Well, that's the crash course in powder boards. If you have any questions, just hit me up.