Worth upgrading to GX1?

There is currently a very good deal on the GX1 (50% off) for body only camera.  I currently own an Olympus E-PL2 and a mixture of Olympus and Panasonic lenses.  Would it makes sense for me to upgrade?  Or perhaps pick up the GX1 and keep the PL2 as a spare/backup.

I own the following lenses (listed in order of how often I use them).

1) Panasonic 20mm

2) Olympus 9-18mm

3) Panasonic 14mm

4) Olympus 14-42mm MKII

5) Olympus 50-150mm

Truth be told, I rarely use the 50-150, I was thinking of selling my 50-150 and 14-42 and picking up the 14-150 Olympus lens, but given the lack of IBIS in the GX1 I would have to go a different route.  There is not really an equivalent Panasonic lens here.

My other concern is how would my Oly 9-18 fare on the GX1?  Is stabilization that much of a concern with a wide angle lens?  I suppose I could just experiment by turning off IBIS on my PL2 and seeing what the results look like.

Or... should I spend my money on another Olympus such as the E-PL5?  It would cost a couple of hundred more than the GX1.

I have 2 primary uses for my camera - family pictures (mostly indoor) and outdoor pictures when I travel (southern Utah or India).  My main frustration with my current camera is the autofocus (both speed and accuracy).

Thanks in advance for any help.