There are numerous software packages, some of them freeware. and yes some of of them are exellent, producing stunning slideshows on TV, which of course will be recorded onto DVD .
I'm at present producing a slideshow of flowers and butterflies. Here is an example of what can be achieved click here
ProwshowGold is probably the best you can buy and may be overkill.
Most burner software packages also contain slideshow software, as does Vista