For example, it was a firmware upgrade which added the 4K Photo feature into the Lumix GH4, a feature which is now standard in all new Lumix M4/3 cameras. About a year ago, there was a rumour that a firmware upgrade would add 4K video recording to the Olympus OM-D E-M1 (which never materialized), and we are now waiting for a firmware upgrade which will add the V-log video format to the Lumix GH4.
The cynical view to firmware upgrades is that the manufacturers use their customers to do the testing: When they find mistakes in how the camera operates, they issue a firmware upgrade. But the positive view is that being able to upgrade all cameras out there allows the companies to stay competitive, and offer more features.
However your view on firmware updates, there are opinions out there that certain manufacturers are better at keeping their old cameras up to date with new firmware, whereas other companies neglect their older cameras and prefer to sell new ones. Specifically, people often say that smaller manufacturers like Fujifilm and Pentax are good at releasing firmware upgrades for older cameras, while the big two, Canon and Nikon, are not as good.
To put this to the test, I have examined two cameras from each manufacturer. I chose one camera which is about 2-3 years old, and one which is around 5 years old. I kept to fairly expensive models, cameras which are often used by amateur photography enthusiasts.
In this diagram, I have indicated firmware upgrades with vertical lines. The period from the last firmware upgrade until now is coloured blue: This is the time in which we have not had any new firmware upgrade.
So what do we see here? The worst contestant is Olympus with the Olympus E-5, the last Four Thirds DSLR released. It had the last firmware version released in March 2012, only 18 months after the initial release of the camera. Perhaps we can excuse Olympus here, since they shifted their focus onto Micro Four Thirds exclusively thereafter.
On the other hand, the last firmware for Olympus PEN E-P1, their first M4/3 camera, was issued in April 2010, which is under a year after the release date, and, of course, quite a bit back in time now.
Fujifilm has a good reputation for keeping their old cameras alive with firmware updates, and this certainly hold for their enthusiast friendly fixed lens Fujifilm X100. It got the last, so far, firmware release three and a half years after the model was initially released, not bad!
On the other hand, Nikon is even better, with the last firmware version for their D700 model released almost five years after the camera was first announced back in July 2008. And neither is Canon very bad, with a host of firmware versions released for both the Canon EOS 5D Mark II and Mark III.
In closing, I don't think it is fair to say that "underdog" camera manufacturers are consistently better at keeping older camera models alive with new firmware versions. Nikon and Canon are also quite good in this respect.
While a firmware update sounds like a simple thing for us users, keep in mind that it is very risky and complicated from a manufacturer's point of view. If there is a bug in the firmware, this could render the camera useless after the upgrade, which would lead to a very expensive and embarrassing recall process. To my knowledge, this happened with the firmware version 1.2 for the Olympus OM-D E-M5. The firmware had a risk of making some cameras inoperable.
So there is a significant cost associated with releasing a firmware upgrade, it is not a small thing.