Update March 31: Via email, Microsoft says the slide in yesterday's presentation was misleading: "Microsoft is not building a native ad blocker with Microsoft Edge. What you saw is a reference to the work we're already doing in bringing extensions to Microsoft Edge, as mentioned in the latest blog as 3rd party ad blocker support."

One of Microsoft's biggest gambles in Windows 10 is its decision to turn Internet Explorer into a legacy product, primarily for enterprise customers.

Its replacement, Microsoft Edge, has been developing slowly since its version 1.0 release with the first release of Windows 10. But judging from a session at today's Build conference in San Francisco, the pace of development is about to pick up.

The feature most power users are awaiting is the availability of JavaScript extensions, similar to those available in Google's Chrome browser. That feature is currently available in Insider preview releases of Windows 10, with one eagerly anticipated extension, AdBlock Plus, already confirmed as an early arrival.

But Microsoft's roadmap for Edge suggests that you might not need that extension. Look at item 4 on this slide from a session titled "Microsoft Edge: What's Next for Microsoft's New Browser and Web Platform."

Extensions are number 1 on that list, with the feature listed as "targeted for next edition," meaning the summer 2016 Anniversary Update (code-named Redstone).

But item 4 on that list, "Build ad blocking features into the browser," is also being targeted for the next edition.

If this feature ships, it will be a much-needed replacement for an Internet Explorer feature called Tracking Protection Lists (TPLs), which added privacy protection into the browser and, as a side-effect, neatly blocked many ads.

TPLs were always controversial, at least in part because at the time they debuted Microsoft had recently purchase aQuantive. That move was an unsuccessful attempt to compete with Google in the online advertising business. It turned out to be a disaster and led to a nearly complete writedown of the acquisition and an exit from the business.

The climate has changed now, to be sure. Ad-blocking has moved into the mainstream, with Apple baking support for Content Blocking extensions into the newest versions of Safari on mobile devices. Opera recently debuted a browser update with native ad blocking as a key feature. The former CTO of Mozilla, Brendan Eich, has launched a startup called Brave, whose chief product is a browser that blocks ads and trackers by default. Google, which derives more than 90 percent of its revenue from online advertising, has, not surprisingly, steered clear so far.

It remains to be seen how the new ad-blocking features will work. But with new features expected to arrive in Windows 10 preview builds in the coming weeks, we probably will know soon.