I'm thinking of going to CO to visit some friends in March (free accomodation near Breck, oh yes). What kind of conditions can I expect. Still powdery or getting slushy?

There is a big difference between the first week in March and the last... It's unlikely to be warm at the beginning of the month.
On the other hand, it can be plenty toasty in the last week of March, even in the Rockies. If you are staying near Breck, you can always go to A-Basin if the weather down low is too warm...

From my experience the first half of March is absolutely primo in CO, tons of sunshine and still plenty of packed and/or fresh powder. Late March might be a bit slushier, but not at the top half of most resorts where conditions should still be great. Lots of college spring breakers on the slopes in March.

Having consistently been to CO for the past several years due to a work conference that takes place, I can tell you that the snow in early to mid March is still awesome! In fact, its not uncommon to get a few snow storms during that time. Two years ago, for example, there was a veritable blizzard blowing at Breckenridge around March 13 (or thereabouts). Local snow squalls, but it definitely made for interesting skiing. Could've used a white cane or seeing eye dog with the visibility limits! Late March definitely gets more iffy. Snow at the base tends to be pretty mushy by afternoon. It freezes overnight and you start all over again with nice stuff until the afternoon when it melts again. The nice thing about Breck is that A-basin, Keystone and Vail are all very close by and lift tickets at any one of those is good at the other resorts as well (very nice for multiday passes).

As Jim K noted, though, expect crowds. In addition to the Spring break college crowd, there are several conferences that schedule around that time (including mine). Also, fair weather skiers are usually out since the weather is usually pretty sunny and nice with good snow.

Some very good advice on this thread.

Depending upon what you are looking for, I would not rule out the first week of April. I've skied Colorado (Vail, Beaver Creek) around April 5 during a very poor snow year, and the mid- and upper-mountain bases were still fantastic. The last 200 foot or so of vertical was definitely slushy with plenty of bare spots, but most of the better terrain is normally much higher up. This better terrain includes plenty of groomed intermediate cruisers. The crowds are definitely much smaller around the very end of March/beginning of April. You'll have plenty of elbow room at the mid-mountain restaurants as you're sunning yourself on the deck.

BTW, the week after that April trip, Colorado was socked in by major snows and winter-like temperatures. It's totally the luck of the draw.

kennedy,

One last thing to mention if you are staying in Breck or real close to it. I stayed in the town of Breck for the first time this past winter. I definitely had problems with the altitude during the first day - I've never had that anywhere else, even with total disregard for the standard altitude adjustment precautions. Several other members of my trip had the same problem on that trip. (We were all fine after the first day.) Breck is a little bit higher than Eagle County (Vail, Beaver Creek) and even other parts of Summit County (Copper in particular). That extra bit made a difference for me, so I'd advise a bit of altitude adjustment. (Don't be afraid to drink beer the first day, just drink less of it )