I assume that it's initializing all the .DLL files that handle the various input and output file formats. ie. AVI, MXF, M2T, WAV, MP3, RED etc. As Vegas handles more formats, I would expect this portion of the loading process to slow down a bit.
I haven't timed it on my machine but it's nowhere near that long.
Creating the file i/o manager is certainly the slowest part of the startup but nothing as bad as you're seeing.
I don't have V9 set to auto open last project and I don't run Media Manager. Do you have XDCAM support enabled?
Just for the heck of it, I timed it again. This round it only took 25 seconds to load. Obviously, my load times are all over the place. But I do (sometimes) see lengthy pauses on the I/O Manager and the Device Explorer.