NO
In-housing all IT is akin to keeping your money in a box under your bed. Does your company keep all its cash in a safe in the basement? no, it keeps it in a bank, so why does it do the same with its data and IT systems. Sure Amazons data center and infrastructure are going to be a big juicy target for hackers just like banks get robbed.Like banks they have some pretty significant security investment for that reason. Read the pysical security section on this document
http://awsmedia.s3.amazonaws.com/pdf/AWS_Security_Whitepaper.pdf
Can you honestly say that your organisation has such safeguards. 12 years working with IT departments across the UK has taught me that almost all organisations are utterly hopeless at security.
"oh yeah the password is adm1n or passw0rd..? what do you men 60 bits of entropy? i cant rember it so i put it on this postit and emailed it to my hotmail"
At least EC2 goes some way to enforcing security best practice with ssh keys and such but you people will still leave themsleves wide open.
So im sure there will be high profile breaches and outages.. its inevitable but the direction and the cost case is set in stone. the internet is just about good enough now that you can stick your IT sytems "over there" and they will work just great, and its cheaper and more secure so happy days, quit bitchin and make sure your CV is nice and up to date.