Their desktop sales have suffered considerably. There's no way they'll be able to ship as many desktop Macs this year as last year. This is the first year they've had negative decline in desktop shipments in a long time year over year, by quarter).
Q1 2006 667 (K)
Q2 2006 614
Q3 2006 529
Q4 2006 624
2434 (Desktop Macs shipped)
Q1 2007 637
Q2 2007 626
Q3 2007 634
Q4 2007 817
2714 (Desktop Macs shipped)
Q1 2008 977
Q2 2008 856
Q3 2008 943
Q4 2008 936
3712 (Desktop Macs shipped)
Q1 2009 728
Q2 2009 818
Q3 2009 849
Q4 2009 ???
2395 (Desktop Macs shipped so far, would need 1317 shipments to match previous year)
The growth trend is towards laptops, so these figures are a simple consequence of market changes that Apple itself anticipated a long time ago...the decline of the desktop has been expected for ages in the consumer IT industry. Besides, you seem to disregard the financial crisis that still affects consumption in the US and most European markets...they are not gonna return to 2007 or 2008 levels anytime soon.