Office 2007 Excel security stronger?

[XP]

I know in the past, MS has come under much fire about how weak file security
is, particularly in XL.

It looks like rather than just a file lock on opening a password protected
workbook, Excel files produced by Office 2007 are actually encrypted?

Does this mean the security in Office 2007 is better? Don't get me wrong, I
know file level security is the weakest form of protection, but it looks like
if Office 2007 uses an industry standard form of encryption, then file level
security may have at least reached the point of respectable (I'm strictly
talking about the functionality of the app itself not password strength,
etc.)?

Thanks in advance for any input and/or links to articles on this subject.