Microsoft has begun advising customers on planned changes to IE now that it has licensed technology from Eolas, however it may have accidentally let slip a release window for Vista SP1 and XP SP3 to boot.

UPDATED The Redmond company said Thursday that it will release an update in April 2008 as part of its regular cumulative update for Internet Explorer that month. Microsoft will make the functionality available via a preview release in December.

"We are simply reverting to the old behavior," senior product manager Pete LePage said. "Once Internet Explorer is updated, all pages that currently require 'click to activate' will no longer require the control to be activated. They'll just work."

In order to appease Eolas, Microsoft made a change to Internet Explorer in March 2006 that prevented ActiveX controls from loading automatically. The functionality changed affected many popular programs that could be embedded into web pages.

However, in August, the two sides made up which likely resulted in a large sum of cash being paid to Eolas, and now appears to have also included some type of licensing arrangement.

This arrangement would uncripple ActiveX as a way to load content within web pages, and is surely good news for developers.

As well as letting users know of the change, LePage also may have let slip the release date of both service packs for Vista and XP. While the service pack for Vista had been expected for the first quarter of 2008, XP Service Pack 3 had been thought to be much further away.

LePage said that these both will be made part of the next pre-release versions of both patches, leading some to believe that the final releases of both could be much closer than previously thought.

However, in an e-mail to BetaNews following the initial publication of this story, LePage denied any connection to the timing of either service pack.