Well Blizzard just earned a few points in my book

Biollante is a mythological imortal plant in north myths, thats why shiragamy named it that in GvB, its a refrence to a legend and not godzilla

Actually I've seen some people who are very familiar with Norse Mythology here say that the name doesn't come up in actual Norse Mythology and perhap Toho came up with the name but wanted it to appear more meaningful so attempted to connect to to old legends not unlike how Gojira was named in the original.

World of Warcraft has made Godzilla and kaiju references before. They have Gahz'rilla and 

Gammerita already, possibly more references in there.

Their chimeras have a rather King Ghidorah-like look to them, too. If this is intended or not is up to debate.

Durp,
A member named Bruticus from Monster Zero did some digging over Biollante's name. While there is no direct connection to Norse Mythology, there does seem to be some loose connections based on English literature. Here's a quote of his findings:

"The closest I could get to a Norse source is Beyla, [Bio] but that's still a long way off from Biollante. But you know what name isn't far off? Iolanthe, [Iolantte] who's a character (based on a real person) from a 19th-century Danish play. The plot doesn't have much connection to Godzilla or Biollante, but the character does live in a garden.

But wait, there's more! The Gilbert and Sullivan opera Iolanthe ... It's actually a little more pertinent to Biollante's origin: this work's [opera's] Iolanthe was exiled from the fairy realm for marrying a human male, and also has a son who's half fairy and half human. It does fit the crossbreeding theme, with Biollante being the combination of Godzilla cells, Erika, and a rose."

Just another touch that makes Godzilla vs. Biollante a little cooler.

You really have to wonder though based on the loose connection if that's just a coincidence there was someone in Norse mythology that connected even slightly to Biollante. I mean in most ancient religions there's normally things mixed between species if they were using that only as a reference they could pretty much take a shot in the dark and hit something.

Huh.

I embedded the images for you. :)

Considering Kazuki Omori's MO, I don't think it's outside the realm of possibility he grasped at some straws from the research Bruticus made. I think what's more likely is that Omori saw one of of those stories and slapped the "Norse" line on it just to simplify the the dialogue. He enjoys glossing over exposition when its the most interesting and lengthening it for less needed things.