The entry for the Urgrosh goes like this,
Urgrosh:
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Superior double melee weapon
Cost: 10 gp
Damage: 1d12
Proficient: +2
Range: -
Weight: 8 lb.

Originally of dwarven make, this weapon has a heavy axe head at one end (dealing d12 damage) and a sharp spear point at the base of the haft (dealing d6 damage).

Properties:
Defensive (A defensive weapon grants you a +1 bonus to AC while you wield the defensive weapon in one hand and wield another melee weapon in your other hand. Wielding more than one defensive weapon does not increase this bonus. To gain this benefit, you need not attack with the defensive weapon, but you must be proficient with it.).
Stout (A weapon that has the stout property can be treated as a two-handed weapon.).

Group:
Axe (Axes are weapons that have bladed, heavy heads and deal vicious cuts. An axe’s weight makes it fine for delivering crushing blows.).


Secondary end:
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Superior double melee weapon

Damage: 1d6
Proficient: +2

Properties:
Off-Hand (An off-hand weapon is light enough that you can hold it and attack effectively with it while holding a weapon in your main hand. You can’t attack with both weapons in the same turn, unless you have a power that lets you do so, but you can attack with either weapon.).

Group:
Spear (Consisting of a stabbing head on the end of a long shaft, a spear is great for lunging attacks.).


As these show the two ends of the weapon are considered two seperate weapons, with completely seperate and intependent proficiency bonuses, damage dice and weapon groups. as this: http://www.wizards.com/dnd/files/UpdateAV.pdf shows it is stated that certain weapon properties only apply to specific ends of the weapon and as it says in the side bar about double weapons "Wielding a double weapon is like wielding a weapon in each hand. In the table, the first line of the double weapon's entry describes the end of the weapon held in your main hand. the indented line line describes the weapons other end, wielded in your off-hand. The two ends of a double weapon can have different proficiency bonuses, damage, properties and weapon groups. . ."
As the entry shows the two ends are of different weapon groups; one is an axe and the other a spear. That means that a feat that effects only axes, like weapon focus (axe), will only give the bonus to attacks made with the axe end and likewise with feats that only effect spears and the secondary end. Therefore a feat like Dwarven weapon training, that specifically says you get proficency with axes and hammers would apply only to axes and hammers and in the weapon group for the secondary end it never says that it is either but a spear so you simply do not get the proficiency bonus, you are not half proficent with the weapon. Also I should say that if I was DMing a game and this came up I would just allow full proficiency but I am arguing about the RAW and nothing else.