The visual bounding box (which is the default bounding box type used by Inkscape) of an object with a filter applied now includes the expanded area of the filter. For single blur filter (such as the blur you apply with a slider in the Fill and Stroke dialog), this expands the bounding box by 2.4*radius; although theoretically, blur is infinite, this is the distance at which the opacity of the object drops below the perceptibility threshold of our renderer. For all other filters, the area is expanded by the relative amounts you specify on the "Filter general settings" tab of the Filter Effects dialog.
Only visual bounding box is affected; if you use geometric bounding box, you will notice no change in most cases. However, the Export bitmap dialog always uses the visual bbox for selection export area; this means that you can now export a blurred object to bitmap without any clipping of the blur.