5 hours.....this way I'm not disappointed...

but honestly 20-30 would be fine with me...

I guess 20 hours but without the extra's.

Maybe around 15 to 20 hours.

Anyone know what other Super Mario games clock in at? 

 I am not sure anymore but I thought if you run through Mario 64 it was around 2 hours but around 8 hours if you want everything.

And for all the stars in Sunshine I took around 15 hours :s.

Lets see.. its on a dvd.. its got huge environments.. huge graphics.. huge amounts of content on a 4gb dvd...

I think anywhere from 15-22 hours.

As long as it takes me to complete it.

I'm guessing 13-15 main game, 15-20 for completionists. When has any mario game clocked in at 40 hours, soriku? It will be an amazing 15 hours though.

 depends on how much you suck...it took me for example 15 years to beat Super Mario bros..

15 to 20 hours to complete it with (roughly) 50% of the stars, 30 to 40 hours to get all of the stars.

 Check Tales of Symphonia. 100 hour game on 2 1.1 gb disks. And 60-70% of 2nd disk data is the same as disk 1. Also huge enviroments and 100% voice acted.