Now that Apple's new MacBook is out and enjoying praise, the spotlight will soon be turning back to Microsoft to see what they can pull off with the popular Surface Pro line. The Surface Pro 4 is expected sometime later this year, but Microsoft knows that it will need to release something special to compete with the new MacBook.

Originally, the Surface Pro line of products competed directly with Apple's iPad, but the laptop/tablet hybrid has advanced with last year's Surface Pro 3 and has evolved into more competition for similarly prices notebook computers from Apple, and even those running Android.

The Surface Pro 3 sold so well that it boosted revenues 24% for Microsoft, equaling a total of $1.1 billion last quarter. If Microsoft can release the Surface Pro 4 at the right time, that momentum would assure big numbers for the new product.

But the question is, what will cause consumers to wait it out for the expected end-of-the-year launch of the Surface Pro 4? Microsoft is already expected to be saving the notebook's release until Windows 10 is ready in the Fall, so that's the most likely window when we'll see the Surface Pro 4 come out.

The Surface Pro 4 is expected to feature 4G LTE cellular functionality for the first time, and enjoy an aesthetic redesign that will cater to customers. As for specs, the new notebook is rumored to have either a 13- or 14-inch display with a smaller 8-inch version becoming available as a Surface Pro 4 Mini.

A Core M Intel processor -- the same one featured in the new MacBook -- would be included, allowing a cooler and less noisy fanless operation that also increases portability. The Core M would also mean a 30% boost in energy efficiency over the Surface Pro 3's Haswell chip.

The Atom 64-bit chipset is also expected as is 16 GB of RAM standard. Storage capacities and other key features as still up in the air as the Surface Pro 4 hasn't even officially been announced from Microsoft yet.

The Motley Fool makes some good points about the comparison of the two products and how the rumored iPad Pro will play into everything. "Apple might not admit it, but its long-rumored 12.9" iPad Pro (which might come with a stylus) is a reactionary move against the Surface and other Windows hybrid devices. Apple's iPad sales fell 22% year-over-year last quarter, but still accounted for 12% of its revenue. By comparison, Mac sales rose 9% and accounted for 9% of Apple's top line. If this trend continues, Mac sales could soon eclipse iPad sales."

It's a given that the Surface Pro 4 will impact Apple's sales with the new MacBook, but just how much will depend on Microsoft's reaction to the Apple product and when the Surface Pro 4 will launch. We're betting on September or October of this year.