That's exactly what I did on the last bike.  I emailed every dealer that had one in stock (it was hard to find an ABS equipped 2010 in July) and took the best out the door offer.  My wife and I rode to the dealership on a Saturday.  I was there for about 2 minutes of paperwork and back on the road lickety split.

It depends on what brand you are looking at and where you are at?

The margins are not that great on Metric bikes and dealers will mark down prices just to compete and look for any MFG hold back money to pay the bills.  Unless you are getting a popular model you should be able to negotiate price.

If you are in a climate where it is getting cold, you may not have a lot of selection right now but what is there the dealer will want gone.  If it is a new model, forget negotiating price...they will get MSRP or more.  If you are having trouble getting the price you want, look to bargain for other add-ons.

If you are shopping look for bikes that have been sitting on the showroom floor for a few months, the dealers sometimes get a grace period from the MFG but after a certain amount of time they have to start paying for the bike and they don't like to do that.  If they can sell it and use that money to pay the MFG, they would rather do that than have to pay the MFG to have it sit on their floor.

Something else to consider, some MFGs base their dealers performance on if they sell more to customers that live in the area they are at.  So your local dealer may get more of a bonus to sell you a bike than you going over to another of their brand's dealers in a different area.  You may add that you are looking at store XYZ in the next city that may add to your bargaining power.

With the invent of the internet all it takes is one dealer that is willing to sell bikes at their cost and publish it to tank it for all of the dealers.  These dealers are looking for high volumes and hold back $$ from the MFGs to make their profits (and selling additional services at time of sale).  The thing is that you have your local shop that needs that $$ to survive and doesn't have to the ability to do large volume so they will push back on the lower price and hope they can get a little more.

The motorcycle business is nothing like the car business.  The volumes are not there and seasonality really makes it feast/famine at most stores.  Trying to work a deal for a bike like a car may be tougher but there are deals to be had.

Something to consider is where you are going to get your bike serviced.  If you are buying new you will probably be bringing your bike in for service for the first year while it is under warranty (or whatever the warranty period is) and you should look at the service dept.  If you like a store and want to bring your bike there you may want to pay a few more $$ to them to make sure they are around when you need them.  Being a customer of a shop does help when you need a hand or are trying to get something worked on when it is busy.

I have seen a lot of 'the lowest price' shops with very poor service departments that I would not want to bring my bike to.

Good luck and enjoy the new ride...you lucky dog.