Yet another multimedia format took a step towards its grave last week when Adobe announced that it would cease developing the mobile version of its Flash Player software.

That move knocked the legs out from under Android vendors’ “our phones and tablets can play Flash” sales pitch. But the multimedia format that powers much of the video on the Internet (as well as some of the most annoying site intros ever made) now looks endangered in more places than mobile devices.

And that presents a problem for gadget vendors in general. Make that, the latest in a series of problems.

Unlike their colleagues in the computing business, electronics manufacturers haven’t had the luxury of assuming that customers can install any extra applications they’d like. These companies have had to build in software support at the factory, which involves guessing what formats will be most popular two, five or 10 years down the line.

I don’t envy them. But I can’t necessarily applaud them either–their forecasts went spectacularly awry in the digital-music space.

There, most vendors bought into Microsoft’s sales pitch for its Windows Media Audio format when they decided to add the ability to play data discs to CD and DVD players. So in addition to the more popular MP3 format, you’d also usually get “WMA” compatibility.

Meanwhile, the AAC format Apple anointed in its iTunes Store got no such support in hardware (not that the Cupertino, Calif., company made any great sales pitch to manufacturers).

Years after those decisions were made, you can only wish they’d gone the other way around. WMA has become a non-factor in legitimate music downloads, it’s scorned by enthusiasts copying their own CDs and it’s ignored on file-sharing networks. The only feature on my DVD recorder more neglected than its recording capability may be its WMA support.

Meanwhile, Apple’s dominant share of the music-download market has made AAC a major part of the music landscape–but good luck finding a new car with an AAC-compatible stereo.

Betting on Flash seems like a similar mistake. But it didn’t have to be. Flash was the closest we’ve come to a universal video format–think of all the different plug-ins you had to install to watch clips online before Flash’s ascendancy. Flash also provided the closest thing to a universal form of the “digital rights management” usage restrictions Hollywood insists upon for video (even as it’s given up on the same in audio downloads).

Unfortunately, San Jose-based Adobe took too long to make Flash a contender in mobile and living-room devices, and when it did the results were less than impressive. And on the most ambitious attempt to make Flash a contender on the biggest screen in homes, Google’s Google TV software, Adobe’s software became an outright liability: TV-network sites could look for the signature of Google TV’s Flash plug-in and use that to block those users from viewing clips there.

Now any device that shipped with Flash support has just had part of its utility foreclosed upon. Adobe instead suggests that the future of video on gadgets lies in apps built with its tools, not Flash clips playing in Web pages.

Meanwhile, browser vendors have worked themselves into a standoff on the two major Flash-free video formats, h.264 and WebM, that essentially forces video sites to provide two different feeds. Plus, the HTML5 standard that accommodates both of them doesn’t incorporate DRM. So on networked consumer electronics, Adobe appears right: We’re looking at an app solution.

But while I’m happy to see connected HDTVs and Blu-ray players include app stores of their own–some of which have won serious support from developers and consumers alike — a universe of apps has issues of its own.

You can find that your favorite site decides that your make or model of TV or tablet no longer warrants its attention–or never did. You may have to pay for app access to a site that’s free on a computer. You have more software updates to tend to. You can simply run out of space to store yet another app.

Unfortunately, that looks like the future we’ve built. So even if you’re happy to see Flash fade from the scene (look, I don’t like those restaurant sites either), is this the alternative that you wanted?