i remember years ago one of the rags posted a rumor about a new "Thunderace R" to challenge the XX and rumored ZX-12. Busa was like an atom bomb though that turned everything upside down. Nothing from yam to date. Would be nice if they did do something though. Maybe if and when suzuki answers kawi's 14, we will see a new hyperbike war with honda and yam getting into it.
Few years back Triumph was working on a busa slayer. Even had spy pics in MCN (real actual photographic evidence..something rare for that rag) of the prototype. One pic of it parked next to a ZX-12R. However, even after loads of money sunk into R&D, triumph brass had the project scrapped and all prototypes destroyed. Stated that they didn't think there was a market for that type of bike anymore.