I wish you good luck, and I may occasionally participate here when a more specialized SE engineering site doesn't exist, but realize that people don't go to a generic "engineering college", nor is there a generic engineering discipline as such. SO is more or less SE's software engineering site; the focus on Computer Science [CS] is rather poor on SO and there are two CS sites in the SE network: one research/graduate and one undergraduate. The same split happens with mathematics SE sites: there's MO and M.SE. This just to show you the degree of specialization that exists in other areas of the SE network.
I'm rather ignorant of how SE sites get created besides, but if you tried to create a single college of engineering where all of mechanical, electrical and what not engineering would be studied, it wouldn't fly. There are loose academic organizations at some universities called "college of engineering", but nobody gets an actually degree in generic engineering. So I think the focus of this SE site is too broad. But since the mod answering this question is the "Director of Community Development for the Stack Exchange Network"... I suppose this conglomerate Eng.SE has blessing from high above. Alas, when I clicked on his user profile that's not what I had hoped to find out, but rather what engineering fields he specialized in... (and I couldn't find out that).
On practical terms, some scope duplication between sites already exists. But generally, this should be minimized and it actually is so in most areas of SE I've seen. For example Superuser considers off-topic webapp questions, which are redirected to that specific SE site. Likewise EE.SE considers off-topic some Arduino questions, mainly those not involving much electronics knowledge. Instead this Eng.SE site seems to invite a massive degree of overlap with its current mission statement.
And I'm not sure that preempting the creation of other specialized Eng sites (that currently don't exist) e.g. mechanical-engineering.SE or civil-engineering.SE is such a good thing in the long run. Also the declared intent in some answers here to absorb parts of EE.SE doesn't bode well.
EDIT to add: What dcorking wrote below made me reconsider some of my "doom and gloom" in the following way: it seems that there wasn't enough critical mass of participants (in Area 51) to get the mech engineering site going (proposal was deleted twice apparently) and civil engineering one appears in a somewhat similar state (although currently not deleted). On the other hand, judging by SO's success in creating closely related spin-offs (I would put programmers.SE, Superuser, ServerFault, emacs.SE and perhaps even TeX.SE directly in this bin) it's quite possible that a catch-all Eng site may actually have the opposite effect in attracting enough participants so that other more specialized engineering sites get created subsequently.