AMD presents "The Bulldozer Blog"

[informal]

Yes, it should be particularly bad (relative to SB) at any number of active threads up to 50% of the cores in the AMD part, especially in integer work. And when the green fans see the gaming results, we'll see the five stages of grief.

Let me get this straight: you haven't seen gaming results for SB,let alone for BD desktop part(or any aspect of BD performance for that matter);you claim that in integer work, with 50% utilization ,BD will be "particularly bad" without providing any source or at least a reason for this line of thinking. All this makes me think that you just failed big time.

First of all,we haven't seen gaming results for SB.It may be great at gaming for all we know.It may be the same as i7 we have today or slightly better.We have few results where Turbo is not working well which show performance uplift up to 10% compared to Lynnfield and a geek bench result from a mobile SB with obviously working Turbo mode which shows ~20% uplift(which is very good).No gaming results yet.

Second of all,we haven't seen any performance results of any Bulldozer variation.Bulldozer will have noticeably improved integer units relative to Stars cores,which will be 4 issue and each core will be capable of 2 loads and 1 store(matching SB core).It will have more advanced Turbo mode too,meaning very aggressive up clocking when CPU is underutilized (the scenario you previously described as "particularly bad"). It will have much more potent fpu unit than Stars cores that can be split in two and will support AVX. It will have more L3 cache and it will have a new shared L2 level cache and probably a trace cache. There is also a hint of a so called "accelerate mode" in which BD's front end can dispatch 2x more instructions to the module's 2 cores under certain circumstances(dresdenboy's blog).There will probably be a lot more prefetching and speculative execution going on in the design too.Now we don't know how much of an improvement all this will bring to gaming(which is mainly a GPU thing) but I think it will bring very noticeable gains in traditional and parallel workloads.
Now it may be the case that when underutilized one BD MPU will trail one SB MPU but to claim this to be the case now ,you would have to have both chips in your hands today and running actual tests on them.Which I'm sure you are not.