Specialized clothing can be nice but is not essential... had a friend do a 120km ride last week in a dress and comfortable shoes.

Used to ride my mtb with slicks 40km a day and it was no big thing... and still like my 26 inch wheels and tyres for commuting.

If it was not for nerve damage in my back I's still be riding on flat pedals or using clips and straps but my left foot forgets where it is and I use spd pedals to keep my foot planted and my knee lined up.

Most often I am riding in everyday clothes with cycling shorts underneath my jeans or riding shorts (mtb shorts) and wearing some mtb shoes which are very comfortable for standing and help with walking because of their stiffer soles.

The things that will make your commute the most enjoyable is being ion a bike that fits you well, that is geared right for then terrain, and having a saddle that makes you forget it is there.

When you have to deal with bad weather or ride in the winter you need to do a little more to make sure you stay dry and warm and that your bike will stay attached to the road.