Impress is the PowerPoint equivalent in OpenOffice. Generally, you can load and present PowerPoint presentations with little difficulty in Impress.
Fonts are often the main cause of problems though, with some MSWindows fonts not available under other operating systems. This manifests itself most often with bullets which use the wingding font in PowerPoint. To have these automatically converted to dingbats in OpenOffice, go to Tools-Options-Fonts. Specify Font as Wingdings and Replace With Dingbats and click the tick. Should fix it, although the bullets are replaced with stars!
Quotes are still a problem in the translation.