Pluspunten
Prestige. People know the company. Employees. Very polite, very nice to interns, competent, smart. Responsibility given to interns. I worked on documents that went all the way to the top of the company. Nice site. Willing to give vacation time to interns. Company name is fantastic for resume when applying elsewhere.
Minpunten
Mergers and general industry trend means pressure for jobs. IT is messy in some regards and slow. Mergers don't help this. Rigid and you can't disclose much of your work outside of the company (even in business units). Comes with the industry, but... No compensation beyond salary. Not even paying July 4th (done in 2010). Tons of contractors and consultants over real employees. Between the first point and this, expecting conversion to a job after the internship is unlikely. Referrals matter a lot to internships. Most of the interns have a parent at VP level or above.