I'm not sure that they will. The litre sportsbike market makes a big noise but it's quite small in terms of sales versus other classes, and extremely expensive in development terms. I've just read Performance Bike magazine July, one headline reads; "Is the Fireblade finished?" This is the '08 'blade, raved about for a year and now considered to be trailing the pack. To stay at the top of the game in litre sportsbikes you have to bring out an innovative new model every two years: the cost of doing this is phenomenal in itself, but when you also consider that every new model means that unsold stocks of the previous one have to be sold at break-even or a loss, it's even worse. The Japanese do it because they're on a treadmill now, and can't stop: at least, none of them want to be the first to stop. They probably still believe that having a flagship litre sportsbike helps sell the rest of their range, and they may be right up to a point.
If I was a manufacturer, I'd be looking to lead the market in classes where model life is long enough to recover development costs and turn a profit - that means big all-rounders like the BMW R1200GS and the 1050 Tiger, sports tourers like the 1050 Sprint and the K1200GS and so on.
It's no coincidence that Triumph and BMW build ranges out of relatively few engines - again, development cost. Will Yamaha port the new R1's crossplane crank engine to other models? Maybe we'll see an FZ-1 Fazer with a detuned version next year - if so, it's that bike that will recover the engine development investment, not the R1.
Triumph seems to me to be concentrating their efforts on volume classes where model life is fairly long, without trying to compete head on with the Japanese in a class that eats investment and produces little profit. They have the 675 Daytona which flies the flag of sporting credibility for the brand (and importantly, gives them a great engine to build a mid-size range just like BMW is doing with the F800; mid-size bikes sell way more units than litre...) - they don't need a litre sportsbike as well. Sure, they could make one using the 1050 lump, but what would they gain? They'd be back on the treadmill, and even if their product was applauded at launch it would be a has-been two years later - they had years of criticism in the press for the 955 Daytona's 'old-fashioned' spec, they can't be in a hurry to experience that again.
In short, it would be dumb for Triumph to launch a litre sportsbike, and they haven't been making many dumb moves lately. BMW can afford to throw money away in pursuit of sporting credibility, Triumph can't and shouldn't.