One of the reasons that I usually wait until the bugs are worked out before buying something new. Fortunately this is a simple fix.

Just applied it to my 15" MBP i7. Here's how it went down: Used software update. It downloaded the files and put up a warning about what was going to happen. I restarted. It installed the other updates (didn't notice what) and then the screen went black and the computer made a 2 second beep. Then I got a gray screen and a progress bar as the warning stated for the EFI update. Once that was done the computer finished restarting. The fan immediately came on full blast because apparently during this process the fan did not run and the CPU ran at full power. The bottom of the computer was very very hot. Good thing I don't have a cheap vinyl sofa, it would have melted.

I'll let you know if this fixed the issues. I did not experience the startup freezes, but I was seeing regular beach balls many times a day. They last a few seconds during which nothing works. There is a huge thread here that chronicles the issue. Some people have had their hard drives replaced which fixed the problem for most. I had not gotten around to dragging myself to the Apple store, so maybe this will save me the hassle.

I will never again install an EFI update on an Apple product.
Been hosed 3 times now. G5, Mac Pro and Macbook Pro.
There's always something that goes wrong and kicks the fans on full blast when they don't need to be.
My $.02

I was having the freeze/stall problem on my 2010 MBP about once a week. After the 10.6.4 update, I haven't had a single one. So I doubt I'll try this update. Anyone else in the same boat?

I have been waiting for this since I bought the 15". Though the stalling was less frequent, once in 2 days for 2 seconds, it doesn't bore well for the expectation that comes with Apple purchase.

I am also going to wait a week before this update. My last Macbook Pro had it's Superdrive destroyed by an EFI (which was cancelled by apple within 24 hours of its release followed by agressive forum trimming to make it seem like it never happened), and about a year after that, another EFI (which was supposed to deal with some display issues) resulted in USB power issues where previously functioning drives and peripherals started popping in an out due to unstable power levels...

I think I'll take your advice. I was about to install it until I read down to your post.

I've only experienced the stall during reboots after a couple of Apple software updates

I had the issue on day two on my brand new MacBook Pro 2010, and again got it last week. Not very funny.

Uh oh. I just bought a brand new one last night to replace my 4 year old one. I ran software update and there were a ton of updates, which I expected on a new machine. I didn't pay attention to what was being applied. Hopefully I won't have this issue.

Fingers crossed.

Finally Apple acknowlege this problem but....

I've had this problem since I got my MacBook Pro with external 24" Mac screen. frequent random freezes that last for 10-20second or even longer, also weird flashing on the monitor. In the last week the external monitor started flashing off then on again like it was resetting quite frequently. So I was really excited to finally see a solution as I've been on to apple care a number of time about this issue. but the genius' didn't seem to know anything about it "have you restarted your computer sir?" yes of course I've restarted my computer!. Anyway the firmware update is not available for my model!!! ie. MacBookPro5,4 aarrrggghhhh!!!

Is it likely there are more firmware updates in the pipeline?