Seriously, who wouldn't want to tromp around in a 10ft~ tall mech suit that shoots fire? I think I'd replace the flamethrowers with steroid-pumped Metroid Prime Plasma Beams though, just for the sake of unlimited ammo.
Comparing that artwork to the Marauder version of it makes me a sad gas mask guy. The Marauder is apparently better from a gameplay point of view, with it's concussion grenades and relatively long range (very Terran) but artistically, no. A flame attack can get cluttery and covers all the area it passes by, and with the Jackal's maximum range of 6 that's a lot of area. The Firebats range of 2 or 3 would have caused less distraction and I think the big Firebat looks absolutely awesome, it's like the regular Marauder but with something extra. I'm ok with Blizzard's choices though. As long as I'll be able to replace, or at least complement my Marauders with Firebats in the campaign.
:spinny: holy crap, great find Fenix! Okay, now imagine if you made that the casing for a paintball gun. I have a feeling just the sight would send people running.