Just looking at the growth numbers over the past two years:
Q1 2008 to Q1 2009: 137% revenue growth
Q2 2008 to Q2 2009: 142% revenue growth
Q3 2008 to Q3 2009: 164% revenue growth
Q4 2008 to Q4 2009: 58% revenue growth
Q1 2009 to Q1 2010: 45% revenue growth
The laws of larger numbers have started kicking in.
But just looking at the trend, here are projected Q2 numbers given certain percentage growth estimate year-over-year.
45% growth = $6.9 million revenue
40% growth = $6.7 million revenue
35% growth = $6.5 million revenue
30% growth = $6.2 million revenue
25% growth = $6.0 million revenue
I prefer year-over-year estimates for each quarter rather than qtr-to-qtr estimates due to seasonality.
But you can do the same sort of exercise using Q1-Q2, Q2-Q3, etc