I own the Olympus EP-1, having bought it about one week ago. Now, the Panasonic GF-1 has been released. Remorses? No. Would I buy the GF-1 if I was in the market for a micro 4/3? Maybe.
First, I much prefer the retro design of the EP-1. For me, part of photography is also how much I enjoy the product, its design and build. The all-metal, retro design of the EP-1 appeals to me much more than the generic P&S look of the Panasonic.
Another point I prefer in the EP-1 is the interface. I used to own an E520 so I'm already familiar with the way the Oly interface works. I also have a Panasonic TZ15 P&S and, although I really like it for what it is, I don't like Panasonic's interface as much.
The flash issue, that is, the EP-1 doesn't have one and the GF-1 does. On the GF-1's side, I must admit that this is a plus. While not very powerful, the GF-1's flash is better than no flash at all. On the other hand, I never was enamoured with the look of in-built flash anyway, so I can't say that I've missed having a flash on the EP-1, but, I'm sure that for some this is more of an issue than it is for me. One thing that worries me about the GF-1's flash, though: it seems quite complicated mechanically - read: I would be a bit worried about it stopping working one day. In many ways, the simpler, the less things can go wrong.
The auto-focus issue, that is, the GF-1 having faster AF. Well done Pana, but again, for me, I haven't come across a situation where the AF's speed of the EP-1 has been a problem. I was aware of the slower AF of this kind if system from the beginning. If I wanted faster AF I would have chosen the Lumix G1, which I considered. I don't do sport action, so this is why I got the EP-1 - because for me its AF speed is fine. Faster is of course better, but the point is, I don't need it. If you want to shoot action, don't get a micro 4/3 - at least not at this stage of its development - and get a proper DSLR instead.
Art Filters on the EP-1. Not a deal breaker, not the main reason why I would choose the EP-1 over the GF-1, but I found these filters much more useful than the cynical me thought initially. I actually really like them and have used them quite a lot.
The Oly colours - in short, the RESULTS I get with the EP-1. And here, ladies and gentlemen, is where the cookie crumbles for me, where the buck stops! In the end, it's the results that matter. For me, I always though that Olympus had the best daylight colours. I owned quite a few DSLRs (as a few of you in these forums might now...

) and I stand by my comment, although this is a highly subjective opinion, of course. But every time I look at the pictures I get from the EP-1, I smile.
Some people complain about the lack of sharpness of the EP-1's lenses (17mm pancake f2.8 and 14-42 f3.5-5.6). And you know what?...Having been through the "shoot the brick wall" and "magnify at 100%" and "pixel-peep in the corners" syndrome, I don't really care anymore. I don't care because great pictures - not that I think that I take great pictures! - do not always have to do with sharpness, or, to be more precise, with "pixel-peeping" sharpness. When I look at the pictures I get form the EP-1, they're plenty sharp for me. I don't magnify them 100% because that's not the way I look at them anymore.
In short, I'm very happy with my EP-1. It does what I thought it would. I was recently on a short holiday and, when previously I used to carry a Nikon D300 and associated lenses, now I carried an DSLR in the palm of my hand while actually being able to hold my wife's hand with my other hand. Nice!

And I still got great pictures. And when we sat down for a coffee, I couldn't help positioning the EP-1 so that I could admire it, from time to time!
So when you you're pondering whether to get the EP-1 or the GF-1, think what do you actually need when taking photos, what you like in a picture, and finally, whether you like the camera itself, its design and how it makes you feel. Why? Because before a picture is taken, you must have a camera with you in the first place. And if you like your camera, you're more likely to take it with you everywhere, like I do with my EP-1.