Toyota's new nose for Turkey already has a lower tip and more downward curve on the top element, so a bridge version is probably being researched indeed. On the other hand, they're sticking with the unstrutted rear wing in contrast to the rest of the field, so who knows.
Torro Rosso will inherit the new Red Bull wing further down the season anyway.
Honda's nose is probably bridgable, but they're probably focusing on getting what they have to work first.
Ferrari and BMW tend to stick to their own solutions and have relatively high noses that could be hard to bridge anyway.
Super Aguri and Spyker are higher nose crowd aswell, might not have the resources to try out too much new stuff. Spyker just went to the nose-connected type, and SA has been testing, but has yet to race, the nose-connected type.
Williams and Renault are currently running nosecones that seem a bit borderline for a bridged top element.
My €0.02 :).