Tesla (NASDAQ:TSLA) CEO Elon Musk has quite the knack for surprising investors. The Roadster was first considered unlikely, and a 265-mile range Model S that would sell better than all comparably priced luxury cars in North America was mostly deemed downright impossible. But Musk delivered. Then, of course, there is the surprising rapid expansion of Tesla's Supercharging network in North America, Europe, and even China. When will the good news stop? According to Musk, there are more surprises in store -- and one is "kind of controversial."

Model S. Image source: Tesla Motors.

Two potential surprises from Tesla
The most recent hint to an upcoming announcement came during the company's annual shareholder meeting on Tuesday.

The hint began with a question from a shareholder about how Musk balances his desire to see all vehicle manufacturers introduce marketable fully electric cars with his fiduciary responsibility to build shareholder value. Summing up his answer, Musk said that he believes electric cars from other manufacturers could actually benefit Tesla. It would help accelerate mass adoption of all electric vehicles -- something that could aid Tesla over the long haul, Musk explained.

Next, Musk dropped some new information.

I'm kind of planning on doing something fairly significant on that front, which will be kind of controversial, with respect to Tesla's patents. But I probably want to write something so I can articulate it properly and explain the reasoning for the decision.

What could the announcement be? It could very well be regarding battery pack and Supercharging patents.

Tesla Supercharger location at Tesla's Fremont factory. Image source: Tesla Motors.

During the shareholder meeting, Musk alluded that he would be glad to share Superchargers with other manufacturers, assuming they contribute their fair share of the capital required. But no manufacturer has yet to approach Tesla, Musk said. Part of the problem, he says, is that there is currently no other electric vehicle that can handle a 135-kilowatt charge. Making the patents behind battery technology and Superchargers less proprietary could help Tesla with its goal to accelerate the adoption of electric cars.

The second forthcoming announcement sounds interesting, but it's getting old. In Tesla's 2013 third-quarter letter to shareholders, one comment went mostly unnoticed.

Tesla is pioneering a new approach to vehicle servicing that we believe will revolutionize the customer experience. An announcement about this will be forthcoming shortly.

Tesla store.

But it has been more than six months and Tesla hasn't made any related announcement. To make sure the media simply didn't miss this "new approach" that will "revolutionize the customer experience," I checked in with Tesla. Sure enough, the company says an announcement hasn't yet been made.

Are surprises required?
It's impossible to refute the argument that Tesla is priced for a very optimistic future, if not a wildly successful one. To deliver on expectations, the company will need to not only execute with incredible precision, but also deliver a few surprises along the way.

Should investors bet on surprises big enough to improve the outlook for Tesla even further? Probably not, with so much already priced in, doing so is speculation -- not investing. This highlights why investors should think twice before they invest at these levels.