If you follow either Microsoft (NASDAQ:MSFT) or Nokia (NYSE:NOK), you've no doubt heard the two longtime partners have (finally) closed their megadeal for Nokia's devices and services unit. The deal was first announced last September and was valued at $7.2 billion at the time. However, in today's dollars, the 5.44 billion euros the two sides agreed on has jumped to over $7.5 billion.

Based on Microsoft's stock price since the deal closed last week, investors don't appear overly concerned with the cost of the acquisition. But that may change this Tuesday, when Nokia announces its 2014 Q1 earnings. Why would Microsoft fans have a vested interest in Nokia's earnings call? Turns out, not was the original deal altered to exclude some assets, rumor has it Microsoft actually paid more than the two sides initially agreed upon. How much more? That's what Microsoft fans are about to find out.

The new deal
When the deal was first announced, Microsoft said it had agreed to purchase "substantially all of Nokia's Devices & Services business, license Nokia's patents, and license and use Nokia's mapping services." There were some questions about the price tag at the time, but investors and industry pundits alike seemed to warm to the notion before long.

The acquisition is a giant step toward Microsoft's objective of diving headlong into mobile, a sentiment that new CEO Satya Nadella recently reinforced during Microsoft's April 24 fiscal Q3 2014 earnings call. And Nokia, though not flying as high as it once did in the mobile device market, remains the clear No. 2 in mobile phone sales, shipping over 250 million units last year.

From Nokia's perspective, exiting its unprofitable mobile business allows it concentrate on its industry-leading mapping technology and money-making networking division: seemingly a win-win if ever there was one. Except once the dust settles -- which in this case will be during Nokia's earnings call if the rumors are true -- it may turn out that Nokia won a little more than Microsoft after all.

When Microsoft general counsel Brad Smith shared the news the deal would close on Friday of last week, he announced a few changes. The new deal, according to Smith, would not include Nokia's South Korean facility, Microsoft agreed to manage Nokia's online presence, and fewer employees would transfer over to the new Microsoft devices and services unit.

Conspicuously absent from Smith's blog post was any mention of Nokia's Chennai manufacturing plant in India, home to about 8,000 employees and where over a dozen of Nokia's phones are built, including several of its Asha line, a popular low-cost alternative in the fast-growing emerging marketplace. As mentioned in a recent article, it was unlikely that Nokia would be able to straighten out its tax problems with the India Tax Authority in time to include Chennai in the deal, and now that's been confirmed.

So what?
As Smith alluded to in his original post, deals of this magnitude are subject to "adjustments," so it shouldn't come as a surprise that fewer Nokia employees are making the switch to Microsoft, and that there will be one or two fewer manufacturing plants than originally planned.

What is surprising, if the rumors are true, is not only did Microsoft receive fewer assets in the deal than initially agreed upon, but it also paid more. Paying more and getting less seems counterintuitive, to say the least. And that's where Nokia's pending earnings announcement on April 29 comes into play. According to Nokia, it will reveal more details during its Q1 call, and Microsoft bulls and bears alike would be wise to listen in.

Final Foolish thoughts
In the long term, regardless of how much Microsoft ended up shelling out for Nokia's devices and services unit, the deal should jump-start Nadella's mobile plans. But in the near term, if it turns out Microsoft wrote a significantly larger check than originally agreed upon, for fewer assets, don't be surprised to see its stock price take a hit. Which way will Microsoft go? That depends on Nokia.

Tim Brugger has no position in any stocks mentioned. The Motley Fool recommends Amazon.com and owns shares of Amazon.com and Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.