It might be little unfair to write off something that I've only read a volume or two of and obviously has so much room to expand, but for now, this is going into the On Hold list.
The story (thus far) is where it lost me. The way it jumps back and forth from seemingly unconnected/barely connected characters and their weapons (who have human forms) throws me off and prevents me from getting to know them better, particularly at the beginning of the manga, where the easiest way to get into the story is to be attached to a particular character. The actual material - collecting souls - is interesting and has a lot of potential, though.
The characters, I can say very little about, except that I like Death the Kidd, the little shinigami who's obsessed with symmetry. He's pretty awesome. The Demon Scythe seems cool as well.
Yes, the art is pretty wacky, but it's quite unique, and I like the oddness of it. It's also fairly easy to tell the different characters apart, which is a good thing, considering the chapters jump back and forth between the different soul collectors. For a story that's totally centered around death and killing people to collect their souls, the art's surprisingly clean and lacks gore, which I like. There is WAY too much fanservice, though. There was a page during the first Death the Kidd story where Liz and Patty's clothes were almost completely stripped off. One minute they're battling a mummy, and next minute, you've walked into the middle of a hentai doujinshi.
That's probably the biggest weakness, plus the jumping back and forth between the characters. Soul Eater already seems quite random, with a wacky sense of humour, and combined with the above, reading just one chapter of it gave me a headache. Perhaps I'll come back to this one, perhaps not.