Tempered glass code is ultimately up to the local area building code but there IRC codes that must be met if your local do not supersede the IRC minimums.

Here is a link that might be useful: Tempered Glass

A few things:
1) While Pella wood windows are arguably decent, their vinyl offerings are not top performers nor are they held in high regard by most pros. Their new 350 series is a step up over the Thermostar however.
2) On the tempered glass, that is not a sales trick. There are some other qualifiers that accompany that, but it is a legitimate issue.
3) On requiring permits, it literally depends on the city that you reside in. Some do, some don't when it comes to simple replacements.

Lastly, I would just stress that in your region, it is IMPERATIVE that you choose a high quality product, especially if you choose vinyl. Look for good structural ratings( air infiltration, design pressure, etc) as they will be very indicative of the quality of the construction.

Anyone know what code would require to have all tempered glass in this case?

The only thing I can think of the proximity to the floor. Most folks just read the first part of the code and skip over the 9 sq/ft minimum exclusion.

+1. The proximity to the floor (glass edge less than 18" from it) would be my assumption as well, just not stated concisely.
I'd also stress the second part of Window's on Washington's initial post, that checking with your local building inspector is highly advisable. They cannot relax any IRC requirements, but they can certainly enforce standards that are more strict. I have had to replace sashes at my own expense after install/inspection because the local inspector chose to ignore that 9 sq ft minimum.

Thank you for all the information, very helpful!

More than likely all of windows don't need to be tempered, maybe Pella was playing it safe. I have had inspectors call me out on tempered glass, but I keep a copy of tempered glass requirements with me.Most inspectors are reasonable and can't remember all the rules let alone glass complicated tempered glass requirements. I only once had to go down town to overule an inspector. my favorite exception is: if the glazing is within 2' of a door and on an adjacent wall and the door does not swing into the glazing it does not have to be tempered or the close less than 36'' rule.

WOW, the link for tempered glass is incomplete on what needs to tempered and what doesn't need to be.

Kudos to you on getting an inspector overruled Todd, but I prefer to keep a good relationship with them, as opposed to getting them overruled and making a fool out of them in front of a homeowner and board. Not much will anger an inspector more than completely undermining his/her authority and credibility.
In addition, as I mentioned, local municipalities do have the legitimate authority to create/enforce higher standards.... Just not worth the time and trouble for me, but I suppose it may very well be for an individual homeowner.

Here is a better link.

http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_3_par111.htm

Here is a link that might be useful: Safety Glass write up

They can not make the rules more stringent just because the inspector says so.They are there to enforce the code not make it.
There is no need to make a fool out of anyone in front of the homeowner/board.I just talked to head inspector and showed him the code.
Usually the inspectors have more respect for you if you have a thorough understanding of the code and would prefer to corrected as would I.
Time spent:45 minutes
Money saved: aproximately $250
Plus I did not have to go back to switch out glass nor did I have temper unnecessary glass every time I had the same inspector. For me it was time well spent

Perhaps the inspectors around here are a little bit more sensitive,lol, although I have never met one that was very happy when you prove him wrong in front of a homeowner. I have found that tactic to be unproductive over the long term.

I'll just reiterate my main points so there is no confusion:
1) local municipalities CAN create AND enforce more stringent standards that he IRC
2) whether you are a contractor or a homeowner, if you are going to need the services of a particular building inspector any time in the future, it is better to have an ally than an enemy, but that is just my own personal experience. Certainly the amount of expense involved should be factored in a well, as there is a big difference between 5 or 10 tempered windows and 1 or 2.
Just my $.02.

As I said I did not make a fool out the inspector in front of the home owner nor would i recommend it.
Municipalities can create and enforce code but you should not let insepctors create there own or non existent code.
I think most would agree it is better to have an ally but if you're going to be dealing with every time it just makes sense to nip it in the butt.1 or 2 windows needing tempered glass can be quite expensive,let alone 5 or 10 plus the additional cost of tempering windows on future jobs where not needed with said inspector.

Regarding the permit. Many cities require permits so that they can track what improvements have been done to a home. Then they use that information to determine what the value of your home is for the property tax assessment.

Additionally, the permit process may trigger an inspection depending on the work done and local codes, and is revenue source for the city.