Adobe Systems is among the software makers testing the market for selling at least some products by subscription rather than long-term license. Adobe (ADBE) on Monday released the latest version of its flagship Creative Suite product -- Creative Suite 6 -- which includes a Web-based version -- Adobe Creative Cloud. CS6 will be available as a subscription service for $49.99 a month in an annual membership and $74.99 on a month-to-month basis with the