I think it was put in as a back up plan. For example if Himym had never had a fourth season, they could have said "Oh it was Stella, they were at the same party" but now it has a fourth season they can move past Stella and introduce a new woman.
So to sum up, no =) Not any more.

i think it might be to obvious and straight forward if it was her. The real significance of that St. Patrick's Day party episode i think might be that the mother ends up being the girl he bumps into but doesn't really acknowledge. Think that might have occured so they could flash back to it down the track. Or i could just be readying way to much into something so small ;-)and Saul_Mikoliunas makes a good point about the Stella reference, which makes sense, have to agree

yes i had a feeling that the girl she bumped is ted's wife!!!! 88percent feeling that ted's wife..

Does it make sense that the girl he bumped into could be Nora, Stella's sister? (Who by the way is freaky hot!!) Do they not look the same?

Interesting theory, but Nora is played by Danneel Harris and the woman at the party is listed on imdb as Nicole Muirbrook Wagner link sorry :)

its the woman he bumped into. shes wearing the same jeans as the woman with the yellow umbrella in the line at the start of the episode. thats what i reckon anyway

Has anyone thght that the narration of the story to the kids is going on. now if the mother was Stella the daughter would know who they met.....no point in having the entire series...ain't it....and maybe the bump has a significance....if they can bring back the slapbet then they can always bring in the St.Patricks day episode back...they are geniuses

if the mother is Stella and the year is 2039, then that girl would not be Stella's first daughter...duh...she would be in her 30's by then.