A while ago, someone had suggested that I check out Weeds (had never seen an episode before).  So I dug up the seasons and I've since made it through season 4.
I definitely see the similarities, although Weeds seems like the desperate housewives version of breaking bad.  More of a comedy feel to it, rather than dramatic.
I have to admit though, the character development is much better in BB.  I find myself kind of annoyed mostly at the Weeds characters, storyline.
		
		
	 
I see almost zero connection between these two shows.
		
 
		
	 
Really?  The two main characters are non druggies thrust into the world of drugs out of economic necessity - there's the biggest similarityBoth shows focus on family as much as the lead characters.
Both characters have run-ins with the law, the DEA connection in both shows (although in weeds it was fairly short lived)(haven't made it past season 4 yet, so not sure where it goes from there).
Both characters are or have been in contact/conflict with the mexican cartels.
Both characters roles involve producing/dealing at some point.
Both shows deal with the territorial issues of gangs/rival gang conflicts.
I see all sorts of similarities, but the difference is in the overall tone and production of the two shows.  I think BB is better written, acted and produced than Weeds - but with that said I think they are totally different genres.
ETA: 
Weeds has nudity going for it, so that's a huge plus.