The biggest thing is homologation, obviously. It's not cheap, and it's tough to get the clearance for a proper DH and SG track due to the needs for A-netting.
As of now, here are the resorts in the east (USA and CAN) that have FIS homologation for downhill:
- Okemo, VT (Chief)
- Sugarloaf, ME (Narrow Gauge)
- Sunday River, ME (T2/Cascades)
- Whiteface, NY (two courses: World Cup DH [i.e. Cloudspin, the 1980 DH course] and Parkway/Thruway/Draper's Drop)
Of these, the only ones that could realistically hold a World Cup would be Sugarloaf and Whiteface (the Cloudspin course), and even then the tracks aren't the most challenging out there. The women may be able to race on said tracks, but the men's tour would likely give these mountains a pass as "too easy."
So that leaves SG as the other option. And here there are more options. There are FIS SG homologations in the following eastern resorts:
- Attitash, NH (Illusion)
- Gore Mountain, NY (Echo)
- Cannon/Mittersill, NH (Baron's Run)
- Mont Édouard, PQ (Desjardins)
- Okemo, VT (Chief)
- Stowe, VT (Main Street)
- Sugarbush/Lincoln Peak, VT (Snowball to Spring Fling)
- Sugarloaf, ME (Narrow Gauge)
- Sunday River, ME (T2/Monday Mourning)
- Waterville Valley, NH (White Caps/Sel's Choice/World Cup T-Bar)
- Whiteface, NY (World Cup/Skyward and Upper Thurway-Draper's Drop)
Of these, the ones that are most World Cup in caliber are Cannon/Mittersill (which was designed as a USST training hill and has a lot of terrain), Sugarloaf, and Whiteface (the Skyward course, not the Thurway/Draper's course). The others have FIS homologation for lower-level competition.
The biggest hindrance to either Sugarloaf or Whiteface hosting World Cup events is their remote locations. They aren't close to many, if any, major population centers or transportation gateways. The closest major city to either one is Montreal, and even then it's via non-highways for the majority of the trip, In terms of logistics, this is a royal pain.
Cannon/Mittersill stands a better chance. Boston is only a 2.5 hours away (Montreal and NYC are 3.5 and 5.5 hours away, respectively), and the resort is on a major highway (I-93), making transport to and from fairly simple. And the race trails at Mittersill are modern and tough, be it for SG, GS, or SL.
Of note is how many eastern Canadian venues have allowed their FIS speed homologations to lapse. Le Massif, PQ, was originally the alpine skiing venue for Quebec City's two Olympic bids, and now the DH/SG track is all but abandoned. Mont Tremblant and Mont Ste. Anne are now just GS and SL. And if you're doing just tech events, Killington has set a high bar.