I believe there are really two lily categories for the future: the mass merchandising and the enthusiasts' market.
In mass marketing as lilies to grow, the current trend is miniature asiatics and that will continue, I agree. LAs, too, although I wonder why they haven't already taken the market by storm. Don't care for them much, myself, so can't really give an opinion. As OTs haven't yet leaped the hurdle of fast and dependable growth despite horrendous care, they have a ways to go. Coming online in the near future will be the everblooming lilies. Included in mass marketing is the cut flower business, too. I predict the next big thing there will be upright(or semi-upright) facing trumpets, with upfacing orientals remaining strong.
For the enthusiasts' market, martagons will continue to grow in popularity, simply because of the greater availability. Alas, I don't think they will ever make the jump into the mass markets, due to the instant expectations of the casual gardener. Frankly, I think that's a good thing, as it keeps them as a commodity only available through real nurseries. Interdivisional hybrids will continue to be very popular, OTs especially as that is the current big trend, but shorter down or outfacing OTs- no. Also increasing in market share will be other oriental interdivisional crosses.
Although I grew lilies from the late 1960s onward, I really did it without outside influence until the second millennium, and wasn't aware of any resurgence of species popularity in earlier years.
(Does this make it a trendy genre, like clothes styles - remember when we where kids, and we wouldn't be caught dead wearing a white belt...
And what do you see guys wearing now?)
My guess is that species will remain a more "in the background" category. But it is true that the availability and discovery of new species will certainly increase the category somewhat.
