Salesforce vs SAP CRM

Just curious about the big picture.

As salesforce speedily takes over the crm market, how will sap overcome this?

SAP has taken several initiatives such as quick deployment and on demand services, what is it that is still lacking when compared to salesforce?

Are there a lot of companies out there which use SAP as their erp and salesforce as their crm.. Is the seamless integration between salesforce crm and sap erp as good as sap crm and erp. What are advantages and dis-advantages of using salesforce with sap erp in place of sap crm..