Mechanical juggernauts will rampage across the big screen yet again in action movie auteur Michael Bay’s Transformers: Dark of the Moon, the third entry in Paramount’s cash churning toys-turned-TV-show-turned-blockbuster movie franchise (and the first to be shot in 3D).

Now the Transformers: Dark of the Moon teaser trailer has arrived and it offers assurances that there will be massive metal men wrecking havoc in the film, but as to the quality of the film’s appearance when viewed in the stereoscopic format (re: 3D) – that issue remains up in the air.

The 3D issue has caused us here at Screen Rant a collective headache in the past as we were led to believe not once, but twice that segments of the live-action footage in Mr. Bay’s third Transformers pic would be converted to the third dimension in post-production – that is, until our claims were swatted down firmly by both studio officials and the director himself. Yet still there are lingering rumors that the film’s CGI sequences won’t be the only bits of footage getting the post-conversion treatment.

As noted in our Transformers 3 Teaser article, Dark of the Moon‘s 3D cinematography will now be subject to an unheralded amount of scrutiny from movie buffs who might’ve otherwise just sat back and enjoyed the sight of crunching metal, explosions, and destruction onscreen without questioning whether it was actually filmed using 3D camera rigs – or converted after the fact.

There’s not enough actual footage in this Transformers: Dark of the Moon teaser to resolve the issue, but expect this matter to be raised again when the next trailer hits – and with our Transformers 3 review, naturally.

Check out the Transformers: Dark of the Moon teaser trailer below:

The atmosphere of this teaser trailer is very much on the dark and ominous side – more akin to that of the original Alien than is to be expected from a sci-fi flick about giant robots. The bit of CGI on display certainly looks as cutting-edge and eye-dazzling as Bay has promised, so we’re willing to wait and find out how it looks in the third dimension – for now.

This preview also gels with previous rumblings that Transformers: Dark of the Moon will revolve around the Autobots and Decepticons being involved in a space race between the U.S. and Russia. Whether a mystical MacGuffin – like the All Spark in the first film or the Matrix of Leadership from Transformers 2 – will be used to get the threequel’s plot mechanics working is not yet clear.

Here’s perhaps a more interesting question – just who is this new robot (see above) that appears in the Transformers: Dark of the Moon teaser? It could be Alpha Trion, who (in Dreamwave’s Generation 1 comics) was a prisoner of Shockwave, a character we know WILL appear in the third Transformers pic. If that is the case, then it’s nice to see that Bay is including certain details in the film that should sit well with longtime Transformers fans.

Transformers: Dark of the Moon arrives in 2D and 3D theaters in the U.S. on July 1st, 2011. Will it be the best of the giant robot trilogy?