Currently DRAW X4 does not show DPI for bitmaps in its status bar.
Here's the macro that displays a separate small horizontal info bar when the bitmap is selected: wx_X4addBitmapInfo.exe
The macro info window can be moved by mouse, I think it's best to put the window right over the object details status bar section.
Read the complete post at http://woxxom-macros.blogspot.com/2008/02/statusbar-dpi-for-bitmaps-in-draw-x4.html