Frequency of Firmware and software updates?

These are the first Intel Macs and a switch in hardware makes the likely of new firmware higher than normal. Software updates are released as necessary and are about on average. Remember, a lot of new software has been released and updates are common in the first few months.

It's common for Apple to release updates to the OS and applications relatively often. Compared to the Windows world, the updates are usually smaller but come out more often, as you have noticed.

There have been firmware updates for nearly every Mac model that has been made in recent years, but the new Intel-based Macs are based on a completely new architecture and still have some small quirks to be worked out, so you'll see a lot more firmware updates than on the PowerPC Macs.

The above answers, are a bit incomplete, let me give you a more accurate answer regarding the Firmware update portion. Generally speaking no it is not common, but this is mainly because adding new features like BIOS Legacy has never happened before. However, the SMC Firmware update is a straight low-level bug fix (new platform quirk as stated in the above comment) to prevent Boot Issues, and does not relate to BIOS Legacy Support.

The EFI Firmware Update was to add BIOS Legacy Support, so that Windows XP can be used. The 1.0.1 update was to add right-to-left (Example: Japanese) Language Support to the BIOS. These type of updates would not have happened on the PowerPC Machines, but it doesn't mean the Macbook Pro is any less reliable because of them.

The EFI firmware update seems to have added the little touch of preventing the disk eject from trying to eject a disk on an empty drive multiple times after the first time it's pressed. These are just little tweaks though, and I've noticed nothing else different after the BIOS Legacy Support EFI update.

Finally, EFI stands for Extensible Firmware Interface and BIOS stands for Basic Input Output System. Both related to intializing hardware, and run a bootstrap program to place the computer in a state where the operating system can be loaded. EFI is Intel's modern replacement to BIOS, which has been around since the first IBM PC.

Updates are a good thing. They generally resolve issues and in some cases, add functionally or other improvements.
Regards,

I don't remember doing any firmware updates on my PB G4 667mhz. Maybe I bought it later in it's cycle so all the bugs were worked out. Either way, as long as apple builds well tested firmware updates, they are easy to locate and install, then I'm good with it. The sad part is that there are a lot of people who don't know what a firmware update is so they may never know to check for the updates and as a result not have bugs fixed on their new machines. I was glad to see apple put the SMC firmware update in the standard software update application rather than a manual download. That will help insure that users get the fixes.

In working on the server side of the world I often would check for firmware updates for RAID controlers etc as part of general maintenance so it's typical of all hardware companies.

Firmware updates are rare once a system is mature. They're not surprising in a major new architecture. I doubt there will be many more. Newer machines have more parts of the hardware controlled by firmware, so it's not surprising to see more firmware updates than in older systems.

If you're comparing to Windows, remember that firmware would be the job of the system manufacturer, not Microsoft. And MS has a separate mechanism for Office updates. So you're seeing more updates partly because the system is new, but also because Apple uses the same mechanism for OS, firmware and applications. I think that's a good thing.

New OS versions are normally every few months.

Security updates are normally once a month.

Applications have their own cycle.

My guess is that the latest firmware update is about all they can do for heat. I expect that they will try to deal with the "whine" in an OS update (hopefully the next one).