Can a hotmail.com email account be cracked?

Short answer, yes. Long answer, probably not.

Any authentication system can be hacked into eventuly by guessing the
password (called a brute force attack). Although this could take a
while (read as years, depending on if hotmail has even the most basic
intrusion detection system, which they would). On the other hand, some
(most) people are ignorent and use easly guessed passwords like
"password", "sex", or "random dictionary word".

There may also be exploits like buffer overflows that could gain you
access to an account by bypassing the authentication procedures.
However, these are rare (not so rare with Microsoft products) and
diffucult to find.

Of corse, my own good sence will prevent me from reveiling any
specifice hacks (if I knew of any) to you as I have a hotmail account
and do not wish it increse the chances of it being compromised.

anotherbrian should post that comment as the answer since the question
doesn't ask us to actually break into an account.

Yes, they can be cracked, in some case fairly easily.

No I won't give any examples.

Alass I would, but I found out about this place after Google stopped
accepting applications to be a researcher. The unwashed masses can
only comment.  :(