Stalker
What do you do when you take a Space Marine Rhino transport and put a nice amount of Dakka on top of it? You get yourself the Stalker anti-aircraft tank AKA Flakka! Its design is based on the Hunter STC, which was found only a few millennium ago (oh really no time at all then. It's not like the galaxy is in continuous war and the design must be used ASAP. Oh wait...)
The Stalker is an air defence tank with an Icarus (I see what you did there...) Stormcannon Array mounted on a Rhino chassis, which allows it to fill the skies with multiple bullet barrages very quickly. With its sensor array it can track targets quickly and take them out in quick succession and is seen as unsubtle but devastating (which in the Warhammer 40k universe where the bigger the gun the better means the Stalker is a favourite Space Marine toy). With extra armour on the front to protect from incoming fire and stabilizers on the sides, it is the perfect vehicle to anchor a defence around. Although in reality most players will single them out as an objective to zerg rush as quickly as possible.
Of particularly grim note on the Stalker is its targeting array that makes it so deadly. Much like the Hunter tank, the secret behind the stalker's accurate fire is because the vehicle's gun is controlled by a target servitor, made from the brain of a chapter serf/failed initiate. While reusing perfectly good head meat doesn't seem so bad by Imperial standards, there's also the possibility of the serf volunteering himself to be the stalker's target servitor. At least in this case, the poor sod still lives instead of being a one-use suicide bomber. This actually sounds a bit similar to dreadnoughts...
It does look like a pretty cool design and the possibilities to just buy several of the Icarus Stormcannon Arrays and convert them into defensive turrets has already crossed the minds of a number of veterans.
