OK, so it's not so great to show up to work smelly. More and more workplaces are offering showers and such, and many gyms offer cheaper "shower-only" memberships.
The main problems with a regular bicycle (cargo/passenger capacity and exposure to weather) are just as present on electrics.
I probably wouldn't have chosen it except that repossessed it from my dad after he never rode it and I didn't want to add a bunch of road/commuting bits to my mountain bike. I originally gave it to him because I was able to get it for cost as an employee at the outfit that made the electronics (AeroVironment).
The advantage of an ebike is basically that it lets you get somewhere faster than you could on a regular bike with the same effort, while retaining all of the advantages in terms of parking and portability. It costs more than the heavy bike it's built on, but is faster than a comparably-priced lightweight bike.
The electricity is basically rounding error on my monthly bill, and it's free when I charge at work.
And while I'm a big believer in the sort of utilitarian fitness you describe, on well-to-wheels basis an ebiker is arguably more efficient than a conventional cyclist eating a typical western diet.
> The ease with which you can slip in and out of traffic, without breaking into a sweat... And there is no battle of wills between pedestrian and cyclist. It is no sweat to restart, so the temptation to zip through a red traffic light, menacing people as you do so, is removed... There are no more scary moments when, as a cyclist, you struggle to gain the necessary speed to cope in busy traffic.
Stopping & starting, dealing with cars & pedestrians all while having to think about conserving your momentum so you don't end up having to balance or dismount with slowed/stopped traffic... these are all things I don't trust myself to do in DC traffic after having just woken up or a long day of work. I applaud those who can, but it's a major impediment for a lot of people (at least in US cities).
The larger problems with winter bike commuting are dangerous road conditions. Ice and slush on the road are bad enough to contend with if you have four wheels, but they can be quite tricky when you have only two. And to further compound the problem is the fact that the bike lanes and side streets that a cyclist prefers tend to be less frequently salted and cleared.
You have to remember that when you are riding a bicycle, you are sweating and a lot of air is moving over your body. The result is that you stay pretty cool, even when it's very hot out. (It's also important to wear wicking and breathable clothes. You are not going to be very comfortable in a cotton T-shirt.)
I want more secure bike parking, more bike lanes, more bike tracks, more workplaces with shower facilities etc. etc. I don't really mind if some of those extra bikes that will be required to push for these things have electric assist.
For me personally I'm not going to rule out using one in the future. I'm so used to biking to work that it is now a non-negotiable factor for me in my employment choices. The existence of electric assist bikes could expand the number of places I can reach with a reasonable commute. And that's not even counting getting old and feeble or having a steep gradient or undulating hills between home and work.
Options are good, and maybe I'm naive but I believe there's more chance of getting folk onto standard bikes if they can dip their toe in with electric assist models until the get confident or fit enough to commit to going without.
That's the big benefit of the bicycle lanes (all over in Cambridge) as I see them: the fact that there's a lane reminds motorists that someone might be cycling down it.
edit: To stay on topic, I bike to work sometimes and know of a few great bike trails around Baltimore if you're interested. As far as commuting in the city goes, yeah, you're S.O.L.
And Baltimore has a bicycle club: http://www.baltobikeclub.org/
The club is probably an advocate for the bike lanes. Lend your support and I'm sure you'll get your better commuting conditions.