A war is brewing in the arcane world of media measurement, and the company that has dominated the battlefield for decades doesn’t look like it intends to cede any ground.

Less than a day after two media-monitoring companies, ComScore and Rentrak, announced their plans to merge in what would conceivably mount a serious challenge to industry standby Nielsen, the better-known company struck back. Nielsen and CBS unveiled an expanded initiative to measure the viewers who purchase the streaming-video service known as CBS All Access. The deal will over time allow CBS to include digital audience measurement in TV ratings. And Nielsen earlier this week said it intended to be able to deliver measurement of audiences across linear and digital platforms by the end of this year.

“While the comScore/Rentrak merger has caught the attention of most investors, we believe Nielsen’s pending release of Total Audience like-for-like audience metrics is actually more significant,” wrote Bernstein Research analyst Todd Juenger in a research note Wednesday morning. “We believe the industry is looking for a better/best measurement solution to its audience crisis. We don’t believe the industry will find that from comScore/Rentrak – not even close.”

To be sure, Nielsen announcements that predict timelines for the availability of new measurement technology have been known to slip. And leaders at companies ranging from Viacom to CBS Corp. have been vocal in recent months about the slackening reliance they place on Nielsen’s overnight TV ratings, given how much more delayed and mobile viewing its taking place among consumers. But if a combination of ComScore and Rentrak is supposed to be a death knell for Nielsen, more than a handful of supporters feel the company has a lot of life in it.

“Our view is that the two research companies will undoubtedly continue to grow, but not necessarily at Nielsen’s expense,” said Pivotal Research’s Brian Wieser. “We see the role of third party measurement becoming increasingly important to large marketers. This allows for growth opportunities from different providers such as Rentrak and comScore, who can offer new services within growing markets and new services that are complimentary to more mature ones without necessarily taking away from Nielsen.”

Even so, there is a palpable craving among media conglomerates for new data. Advertisers that once placed commercials in “pay and spray” fashion across a TV-network schedule now are demanding precision, hoping to place tailored commercials alongside programming they believe will reach a very specific consumer – a first-time car buyer, say, rather than an adult between 18 and 49. ComScore has long measured digital audiences while Rentrak uses technology to analyze set-top box data from cable distributors.

Media companies, who have long grumbled about an overreliance on Nielsen, will likely enjoy the entrance of a bigger player with more heft. “The newly formed entity will help bring needed competition into the field of cross-platform audience measurement,” said Jane Clarke, chief executive of the Coalition for Innovative Media Measurement, a group backed by many of the big media conglomerates. “Certainly, this is a field undergoing significant pressure to innovate in response to quickly evolving consumer content consumption habits.  It is the proliferation of measurement options available to the industry that will help breed much needed innovation.”

Collaboration between ComScore and Rentrack has the backing of a prominent industry player: Sir Martin Sorrell. His British advertising conglomerate, WPP, is an investor in both Rentrak and ComScore, and could hold up to 19.9% of the new company after the two parties complete their transaction. To Nielsen supporters, Sorrell’s presence behind the scenes might suggest a lack of some of the independence under which Nielsen operates.

In an interview with Variety Tuesday evening, ComScore CEO Serge Maata and Rentrak CEO Bill Livek said WPP would not have seat on the new company’s board of directors. And they said they already did business with many advertising companies not associated with WPP.

As for Nielsen? “When we wake up in the morning, we don’t think about them,” said Livek, who is expected to become president of the new ComScore. Others do and will, however, meaning that the company’s “old reliable” could be battered, but isn’t yet broken.