Update: now try this method

Revit Architecture 2012

Revit Structure 2012

Revit MEP 2012

I recommended using Firefox with Downthemall to download these files. Finally, be sure to confirm the checksums / hashes before beginning the install.
EDIT:  Some people were having problems with these links.  However, this should no longer be a problem.
If you are interested in Student version links, go to this page.

Revit Architecture 2012

Revit Structure 2012

Revit MEP 2012

I recommended using Firefox with Downthemall to download these files. Finally, be sure to confirm the checksums / hashes before beginning the install.
EDIT:  Some people were having problems with these links.  However, this should no longer be a problem.
If you are interested in Student version links, go to this page.

Here it is:

http://revit.downloads.autodesk.com/download/2012RAC_RTM/Autodesk_Revit_Architecture_2012_English_Win_32-64bit.exe

Here is the readme:
http://revit.downloads.autodesk.com/download/2012RAC_RTM/Docs/Revit%20Architecture%20Readme.htm

System requirements:
http://usa.autodesk.com/revit-architecture/system-requirements/

Remember where you heard it first!  And feel free to subscribe.

Here are the Checksums:

File: Autodesk_Revit_Architecture_2012_English_Win_32-64bit.exe
CRC-32: 5d535905
MD4: b236bc16568bbd91fdcc37b50f7f1cd8
MD5: 458cc0362a27805442728822c9bbd317
SHA-1: 614694bbde06fb280606a10f2302eabd85365821


https://wrw.is/2011/04/revit-architecture-2012-student-version.html


https://wrw.is/2011/04/revit-architecture-2012-file-details.html

https://wrw.is/2011/04/revit-2012-suites-available-for.html

If you download the Student Version, maybe you could comment if the Checksums are the same or different?