People take jobs in new fields every day. But rarely do career changes set off the fevered analysis and speculation that greeted Morgan Stanley chief financial officer Ruth Porat's decision to ditch Wall Street for Silicon Valley.

Porat's new role as Google CFO resonated across the business industry for a number of reasons. Some commenters took her move as definitive proof of the tech sector's triumph over banking in the war for top talent. Others pointed out that Porat's move further thins the ranks of powerful women on Wall Street. Still others wondered whether Google poached Porat in order to bolster its relationships with banks as the tech giant makes forays into the world of financial services — or if it wanted Porat in order to better compete with them.

Here's a roundup of smart, skeptical and sly observations raised by the Twitterati.

Financial advisor and CNBC host Josh Brown suggested that Wall Street can't hold a candle to the appeal of Silicon Valley:

Bloomberg View columnist Matt Levine compared the responsibilities of a CFO at Google and Morgan Stanley and discovered a clear winner:

That opinion was shared by Stone Street Advisors founder Jordan S. Terry:

Pundits are already weighing in on how Porat's presence will influence Google. Analyst Colin Gillis told Bloomberg that Google needs her to keep a close eye on expenses, since the company is full of "people who want to pursue big ideas" by dipping into the company's large pocketbook. But risk analyst and The Black Swan author Nassim Nicholas Taleb suggested that the last thing Google needs is more corporate restraint:

Reuters' Peter Thal Larsen suggested that Google's dreams of usurping banks may have played a part in the company's choice of CFO. (Indeed, industry experts tell American Banker's Andy Peters that her experience in banking and finance was likely part of the draw.)

Meanwhile, Fusion's Kevin Roose considered the dearth of high-ranking women in banking and finance in the wake of Porat's departure.

Commenters named JPMorgan Chase CFO Marianne Lake and JPMorgan asset management chief Mary Callahan Erdoes as the powerful women now on Wall Street, prompting this observation from Bloomberg columnist Katie Benner:

And Reuters' Lauren Tara LaCapra suggested that sexism may have limited Porat's ability to rise further at Morgan Stanley.