I thought that the Hummingbird A8 chip that Samsung developed was combined with the 1 GHz Snapdragon processor.
Nope, they're entirely different processors made by different companies, and have nothing to do with one-another (aside from being direct competitors).
The Snapdragon is essentially a completely custom processor designed by Qualcomm, while Hummingbird is a modified Samsung ARM Cortex A8.
While Snapdragon has roots in the Cortex A8 and runs the same ARMv7 instruction set, it is essentially a complete rebuild of the processor.
Hummingbird, on the other hand, IS a Samsung Cortex A8 that has been modified significantly by Intrinsity, the company you may have heard in recent news was just purchased by Apple.
The reason we've not seen a 1 GHz Cortex A8 is because until this point, it's not been possible to release it at a stable 1 GHz. However, Hummingbird is the first production 45 nm ARM processor that we've seen announced in a smartphone. This reduced scale allows for about 20% more clock speed and power efficiency, hence the ability to clock at 1 GHz. Snapdragons on the market are currently still on the 65 nm feature size.
Basically, Hummingbird is the best SoC (System on a Chip) on the market right now for 2 reasons: it's the first 45 nm smartphone SoC we've seen, and its modifications by Intrinsity allow it get more performance per clock cycle than a typical Cortex A8.
It's tough to say if it beats a 1 GHz Snapdragon in performance currently (it appears they're pretty neck-and-neck), but it definitely is significantly more power efficient. Add Samsung's claims of 4x the graphics performance that the current Snapdragons offer, and the result is a pretty impressive.
Hummingbird will lose out in performance to the 45 nm 1.3 GHz Snapdragon released later this year, and both will be overshadowed by the Cortex A9 SoCs released early next year.
But for the time being, Hummingbird is the best you can get in a smartphone. My article covers all this and more, in detail.