The Coldfusion 9.0 Update 2 release document (http://helpx.adobe.com/coldfusion/release-note/coldfusion-9-0-update-2.html) states "do not install ColdFusion 9.0.2 alongside an existing ColdFusion 9.0 or ColdFusion 9.0.1 installation". Does that mean I cannot install the update to go from v9.01 to v9.02?
That is correct. As stated in the referenced doc CF 902 is a full product installer. You can be on the same update level as 902, if you apply CHF1 and CHF2 and the released security fixes for CF 901. With CF 902, Adobe excludes Verity from the CF9 installer, due to contractual obligations. Ref. http://blogs.coldfusion.com/post.cfm/availability-of-coldfusion-9