Sun must have a huge smile on their face recently, as they see for the second quarter in a row tremendous growth for their server products. With server revenue totaling $1.6 Billion, they saw a 14% increase according to Gartner research group. Even though they still fall far behind giants HP and IBM, they are surpassing Dell in some areas. Dell still beats them in terms of volume, but is seeing much less growth. Sun's choice to begin using Opteron processors has clearly affected this, as the article points out:

Sun's fortunes have been boosted by strong sales of its Opteron-based servers and higher than expected interest in its UltraSPARC T1-based servers. The company's focus on energy-efficient servers looks like the right call given current trends in the marketplace.
While for many businesses, price is important, quality and reliability often come above price as factors when decided what gear to buy. If Sun demonstrates an Opteron system running Solaris that is rock-solid and carries the “Sun” label and support, it probably won't be hard for them to sell it over a Dell server running Windows SBS or something of that nature.