Transfer page 1, position 1 to a new page

Our web sites home page is number one for a particular keyword that drives a lot of traffic our way. Our business has now grown with new products and we need to change the home page and want to create a new page that targets that keyword and the home page will cover all of the products.

As an example this is what we have now:

Mega widget<-- home page about Mega widgets, page ranks #1.

What we need:

Widgets <-- home page needs to be more generic because we now sell multiple widgets.
|_ Mega widget <-- we want to create a dedicated page for Mega widgets and maintain #1 pos.
|_ Super widget <-- first new product.
|_ Ace widget <-- second new product

My question is, if we set up this new structure will the new Mega widget page keep the #1 position?

Any advice or strategies on doing this kind of thing, it must be reasonably common.