oh .... and reading questions SHOULD be part of the skillset <g>.
1. Technical Expertise (you really need to know the ins and outs of your product / service AS WELL AS those of your competitors.
2. A "Sales" personality. The best SEs are those who are not just techie "dorks" but are able to understand business value and how to articulate your company's value proposition.
3. Self-Discipline : There are often a lot "empty spaces" in a SEs day, especially around Q3 when all your customers are on vacation, and it is hard to schedule a sales call. A really good SE spends that time updating skills / knowledge without prompting from a manager.