They most certainly will.  If they didn't, they'd have no reason to carry the device.

Retailers generally get less than $10 per console sold.  Sometimes they actually lose money per console sold, as is the case with the ps3, where after taking into account shippping costs from their warehouses to stores, GameStop loses ~20 cents per console sold.

Where retailers make their money is in software sales and (even moreso) sales of accessories.  New games running $50-60 garner retailers a profit of $8-12, while accessories like controllers can net them up to and above $30 (it's around $35 on a DS3, I believe).  (The non-existent margins on consoles and not-so-great margins on new games are why almost all dedicated game stores dabble in used goods, fyi.)

With the PSP Go!, retailers don't have software sales to fall back on, neither new or used.  Even accessories aren't a great market, given that people don't need to buy extra controllers or anything of that sort for a handheld.  Because of this, Sony has to increase retailer margins on the device significantly to give retailers any incentive to carry it.

Despite the already high price, many retailers are still threatening to not carry the device, going so far as to put the launch of the console in France in question.  According to my District Manager, GameStop Corporate was having a heated battle with Sony over this a number of months back.  Patapon 2 being sold through retailers via promotional code despite being a PlayStation Network title is a direct result of this battle.

Sony has to increase retailer margins on the PSP Go! considerably, or they'd have nobody selling the darn things.

And please, refrain from insulting another user's line of reasoning ("those opposing arguments seem a tad shallow").  It's even worse when you follow such a line with bold statements that are nothing more than baseless and ill-informed assumptions.  And yes, this last line was totally hypocritical.