There were three big events this week — Microsoft’s PDC, SC09 and Dreamforce — and today belongs to the latter. Salesforce.com made news with its Chatter platform, but also is getting a taste of its own medicine from SugarCRM, which is giving away its anti-Salesforce.com “book” “Behind the Smokescreen” outside the Moscone Center. The company also sent a scathing e-mail to the Dreamforce press list. On top of this assault, Salesforce.com has to deal with actual product competition from MindTouch’s new cloud-based collaboration service. Benioff and Co. have enough market-share padding to absorb these offensives, but they are a sign of tougher times to come in the SaaS market.