The Federal Rules of Evidence were restyled, and the new version became effective on December 1, 2011. Here is a link to the restyled version of the Rules, which is defnitely worth reading. As a sample, the restyled version of Fed. R. Evid. 702 is as follows:
Rule 702. Testimony by Expert Witnesses
A witness who is qualified as an expert by knowledge,
skill, experience, training, or education may testify in the
form of an opinion or otherwise if:
(a) the expert’s scientific, technical, or other specialized
knowledge will help the trier of fact to understand
the evidence or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and
(d) the expert has reliably applied the principles and
methods to the facts of the case.
A copy of the Report of the Advisory Committee can be found here, and discusses in some detail the contributors to the effort to make the Rules more easily understandable. Among other things, Bryan Garner's legal style guide was used in the rewrite of the Rules.
As reported by BeSpacific.com, there are also amendments to the Federal Rules of Appellate, Bankruptcy, and Criminal Procedure which also became effective on Dec. 1.