Mac shipment and growth rates
Apple shipped 1.227 million desktops and 2.907 million portables totaling 4.134 million units during the quarter.  The earnings report highlighted this new record and the fact that shipments increased 23 percent on a year over year basis.  Here's what Apple stated in their earnings press release:

"Apple sold 4.13 million Macs during the quarter, a 23 percent unit increase over the year-ago quarter."

This metric sheds some light on growth but it doesn't tell the whole story.  When the numbers are analyzed (via the graphic below) we can see that the Mac growth rate has slowed for the second consecutive quarter on both year-over-year and quarter-to-quarter (sequential) bases.  In fact, the sequential Mac growth rate hasn't been this low since Q2 2010 when shipments declined 12.46 percent.  Let's look at this another way, by disregarding the routine Q1 to Q2 shipment decline over the 2010 - 2006 period.  If we do, the Q1 2011 sequential Mac shipment growth rate was at its lowest since Q1 2009, a period of two years.

So what does this tell us about Mac growth?

• Mac shipments are increasing.
• A new Mac record has been achieved for three straight quarters.
• Portables are outselling desktops by more than a 2:1 ratio.
• Mac growth has slowed for two consecutive quarters.
• Mac growth has slowed over three of the past four quarters.

Is the iPad cannibalizing Mac growth?
During the earnings Q&A with analysts yesterday, Brian Blair of Wedge Partners and Apple COO Tim Cook had a