I have an E-PL1, but my answers might help anyway.
I don't have one yet. I decided to see how I go with the LCD first. If either Panasonic or Olympus release a rangefinder-style camera with built-in EVF then I'll possibly buy that instead.
I have 2x8GB class 10 cards made by Delkin. Wouldn't recommend them: they seem to perform well but the brand sticker on one of them started to come off in my iMac card reader. I'll be extra-careful from now on.
Always. They're small enough to carry easily. You charge the battery much less frequently when you can just run it down until it stops, which is better for the battery too. The E-PL1 seems to chew through its battery fairly quickly.
I have the Olympus 14-150mm as a companion to a Panasonic 20mm. For me, this seems to be an excellent travel kit (which was my reason for buying), giving me versatility and compactness. You won't get image stabilisation with this zoom though, making it slightly less useful on the GF1 (i.e. you'll be limited to reasonable lighting conditions or need a tripod)
None yet. I hope the 14-150 is wide enough, but I'm interested in the upcoming Olympus wide prime. The Panasonic 14mm is a bit of a disappointment for me: not wider than my zoom and the reviews suggest performance is only average. I'd think about the 9-18mm and 7-14mm wide zooms, but I don't think the expense is justified for occasional use.
Other stuff:
- A PacSafe "Metrosafe" 200 shoulder/mini-messenger bag. Just a small-ish general purpose bag with some security features. Will fit a water bottle and umbrella in side pockets. Plenty of space inside for camera, lenses etc.
- An anti-static lens/lcd cleaning cloth that stuffs into an attached pouch. Works well.
- A Joby Gorillapod SLR mini-tripod. Seems stable with the camera attached but I haven't used this in anger yet.
I also want to buy a macro/portrait lens, but the Pana/Leica 45mm is too expensive for me. If the proposed Olympus 50mm macro (due Q1 next year) offers a reasonable price/quality combo then I'll probably buy. Otherwise I'll play around with some adapted lenses and manual focus.