After last month's post about five keys to the iPhone vs. Droid fight, we had a lot of feedback come in, and there were big announcements from Apple and Nokia.  Here are a few highlights and key points to learn from.

Droid development is already getting hard

I had a number of developers write me about their experience with Droid development, and the feedback I got echoed that Droid development is harder because of the range of platforms you have to target.  Not just the screen size, but checking whether the device has various accessories such as GPS, digital compass, camera capabilities, video formats, and connection speed.  This makes it harder on the developer to check everything in the user's device, and then try to adjust and provide a positive experience for all devices.

Angry Birds is the most widely installed iPhone and Droid app, and they recently shared their sense that the iPhone will continue to be "the No. 1 platform for a long time from a developer perspective."

As the Droid handset options grow, app development will become harder. This in turn will lead to fewer apps, resulting in a less attractive device for users.

Size matters

Apple just announced the iPad 2 in the past week, which unimpressively has a screen size and resolution identical to the original.  After creating the most successful consumer electronics device in history, and spending a year in product development, Apple managed to make a 0% improvement.

Was this a case of Apple resting on its laurels?  I would argue that this is part of a deliberate strategy to keep developers happy by limiting the number of platforms they have to target.

The Motorola Xoom is clearly better hardware than the iPad and iPad 2. It has a 20% bigger screen, free upgrade to 4G from 3G when available, and HDMI and USB ports, just to name a few improvements.  But as any iPad user can account, it is extremely unsatisfying to install an iPhone app and click the 2x zoom to stretch that small app to the full size of an iPad.

Without apps that take advantage of that better hardware, it's not a compelling reason to buy.

Microsoft too far behind

Imagine that you've just signed a deal to use Microsoft's technology and Microsoft will pay you billions of dollars as part of this deal.  You'd think that's a good thing, right?

Unfortunately, it was anything but good for Nokia. Just as they confirmed that Microsoft will pay them billions of dollars in incentives to make Windows Phone 7 the primary operating system for their smartphones, Nokia's stock fell dramatically.

Microsoft's mobile platform is considered so far behind that the world's No. 1 phone manufacturer is getting killed for prioritizing Microsoft.  Kudos to Apple and Google.

Conclusion

Although Apple might provide the easiest platform for developers, the bottom line is that the others cannot be ignored. If developers want to sell their apps, they have to reach fans no matter what device they are using — laptops, phones, tablets, or anything else.