All of these companies (except RIMM) generate substantial free cash flow. I look at what they are doing with these cash flows recently.

MSFT: bought Skype for 8B. Any synergies so far? Hard to see.
They are also throwing bunch of money at Bing.com

INTC: bought McAfee for 8B. A chip maker buying security software. Makes no sense whatsoever.

HP: bought Autonomy for 10B to compete with SAP. This move was considered so bad that CEO was fired.

Compare these with Dell. Yes, 2009 acquisition of perot was hard to understand. However, recent acquisitions of SonicWall, Quest software make lot of sense. All are relatively smallish tuck-ins which directly support their move to become enterprise hardware vendor.

Plus, the founder / owner Michael Dell is very much in charge.