There has been much speculation and rumor since Ebbe Linden revealed LL's work on a follow-on grid to SL, which is called Sansar at this time.
Rather than panicking, please educate yourself about what has actually been said on the topic by reading and viewing the original sources. Commentary from other sources should of course be taken with a grain of salt; however, we recommend Jessica Lyon's posts (on the Firestorm blog; see specific links below) as a good place to start.
Linden Lab have gone to great lengths to assure Second Life residents of their continued support and investment in the Second Life platform. With the recent launch of Bento and the Visual Outfit Browser amongst other new features, alongside increases in prim allowances for all land owners, there should be little doubt as to the sincerity of this commitment. To underline this further, Firestorm's own Jessica Lyon joined Patch Linden and a number of other prominent Second Life residents to discuss hopes and plans for the future of Second Life. Links to the show and further information can be found in this Designing Worlds Blog Post
If you wish to discuss the topic, please do NOT do so in Firestorm support groups. Please discuss it in The Phoenix Lounge in-world group, or in other groups of your choice; or in this (long) discussion thread, where Ebbe Linden answers some questions.