MovieFactory, PictureShow and VideoStudio are all capable of burning DVD discs that will play on computer DVD drives and standalone DVD players.
PictureShow actually has a few slideshow features that aren't available on MovieFactory however it is strictly 4:3 aspect ratio (no widescreen) and (as Steve mentioned) for Win XP only. MovieFactory is a multi-purpose program that offers most of the slideshow features from PictureShow and adds some additional capabilities in the areas of menu customization (authoring), disc copying and video clip editing. It is also capable of outputting in both 4:3 and 16:9 aspect ratio as well as high definition (with optional PowerPack). Of the two programs, PictureShow is the easiest to learn although the slideshow UI in MovieFactory is somewhat similar and certainly not difficult. Neither of these programs allow you to combine slides and video clips in the same show. VideoStudio has a slightly steeper learning curve but (in my opinion) is the most intuitve timeline editing software on the market. The benefit is complete control over virtually all aspects of your slideshow and movie projects. If you feel you might want to expand your creative options at some point, VideoStudio is well worth consideration.
As for more specifics on these programs, Corel publishes comprehensive feature brochures in PDF format for all of these. I'd highly recommend that you view them for purposes of comparison.
VideoStudio 11.5 Plus
DVD MovieFactory 6 Plus
CD& DVD PictureShow 4
Regarding similar software made by other developers, we really can't go into great detail as this forum is primarily for discussion of Corel, Ulead and Intervideo products. That said, understand that all video editing programs, no matter how simple they may be to use, are very complex in their make up. Because they draw upon so many resources and configurations within your computer (and also must interact with changes that have occurred within your computer over time), all are subject to possible crashing and/or other issues. For this reason it is ALWAYS recommended that you experiment with trial versions before deciding on a specific program. In short, investigate the features of various programs, narrow your choices, experiment with the trial versions, and then purchase the software that best meets your needs AND runs well on your PC.
Hope that helps