Like JaneH, I have mixed feelings, though from the surer-footing (ballet-wise) of Europe.
I'm more disappointed that Wheeldon will likely have less opportunity to work with larger casts. Perhaps he will still be able to do a ballet or two each year as a guest choreographer, but one assumes his pieces for his company will be smaller. But I think he's one of the few young choreographers today who has the pedigree and talent to do the story ballets in an interesting way - I loved his "Swan Lake" as well as his "Carnival of the Animals".
While I do deplore the 'star based' system of companies like American Ballet Theatre, my feeling is that the smaller companies actually provide more opportunities for younger dancers. Many of the smaller companies like Peter Boal's now defunct company, the touring groups run by NYCB dancers, Ethan Stiefel's pick up group, and the RDB touring group almost always include a bunch of corps members and younger soloists. And these dancers benefit immensely by getting to work with more experienced dancers and choreographers, rather than being another body in a corps. Sean Suozzi, for example, is a dancer who I think made great strides via his experiences in Peter Boal's company.
My impression is that Wheeldon's Company is, for now, more a pick up company, and thus is probably starting out with principal dancers most likely because they have more say over their schedule/contracts and so are more likely to be able to take time out to dance in his company.
I would definately agree that big ballets are becoming more and more the preserve of the larger companies in the US. It's a strange situation because story ballets are what companies seem to think draw in audiences, but many smaller companies just don't have the resources to put them on properly. So you get half-witted attempts that probably hurt more than help draw in ballet audiences. One solution is the shared productions which have been successful in the US.
From my perspective I have mixed feelings - here in Scotland, I think going away from a more traditional company was the only way to save the Scottish Ballet. For better or worse, there just isn't the money (or, honestly, enough homegrown talent) to keep a large, classical company going. And the new format has really been excellent, though it's still a work in progress. But at the same time, I often feel starved of traditional ballet here, as I think Scottish Ballet has sometimes moved to far towards contemporary, and relied too heavily on the choregraphy of Ashley Page, the AD, who I think is a great AD, but not a good choreographer. Which would be fine if we got classical companies touring here more than once or twice a year, but we get a ton of excellent contemporary companies (Rambert, Alvin Ailey, NBT's pseudo-ballet story productions, NDT, SDT etc. etc.). Once in a blue moon ENB or BRB come up here, but I think it would take more than a miracle to get the Royal Ballet up here even thought the Scottish Ballet now goes to London. So we rely on the Festival each summer for foreign companies like Pennsylvania Ballet or Het Nationale Ballet. It wasn't until last month when I got to the Royal Danish Ballet and saw two full lengths (Swan Lake, Napoli) that I realized how 'starved' I was for good, meaty classical ballet where there are enough men in a company to do a real corps ballet.
Anyway, I think, however, that the situation is less precarious in Europe. Thanks to government funding, the national ballets in most European companies can still afford to properly put on the classic ballets. Perhaps it is cultural too, for the classical full length ballets were born in Europe, whilst it is Robbins, Balanchine and other neoclassical choreographers who define ballet in the US.