My rule-of-thumb with all new software is to purchase now (or when prices are low) and install after the first service or maintenance release. This is also the case with Timeslips 2012. There have been a couple of issues that could be problem for some users. Timeslips has issued "patches" for both problems. I recommend that you contact Timeslips to get one or both patches if you need to install your Timeslips upgrade before the first service release comes out. If you can wait for the service release, both patches will be included along with other minor program changes.
One thing to keep in mind if you are waiting for the service release before you install your software: Timeslips free 30-day technical support starts on the day you place your order. By waiting for the service release, you may forfeit your free 30-day support.