With New Zealand expecting Vodafone to announce the launch of its first 4G mobile services on Thursday, TechDay now has reason to believe it has something else up it's sleeve.

Industry rumours have almost made tomorrow's announcement a formality, but the telco's coy nature on the topic suggests all is not right.

After publishing our take on the scheduled media event earlier today, the common consensus is Vodafone will move into the 4G arena, and increase it's competition with rival Telecom.

Yet an unnamed source seemingly close to the company begs to differ, offering the following comment:

"No, I don't think this will be the 4G announcement," he says. "They need to square away the 700Mhz spectrum before we get too excited by that."

So if the ace up Vodafone's sleeve is not 4G, what is it?

"My guess is this will be Vodafone's foray into the set top box market," he says. "Something they've been working on for the last couple of years - they even poached a Sky executive to head up the project."

Despite quickly removing the comment from our grasps, the opinion adds another dimension to what seemed a relatively straight-forward announcement.

"OK, we admit it. We’ve been keeping a very big secret," Vodafone told the press this week. "But we’re ready to show you just what we’ve been up to – and we think you’ll like it."

And while such talk is merely speculation, or idle gossip at that, the comment raises questions ahead of a big day for the telco - question is, what will make it so big?

What do you think Vodafone will announce? Tell us your thoughts below