Nintendo are controlling stock levels, they release more stock when a big title is released and then they pull back again. The overall trend is upwards though and this is due to increased production. They need to make sure that they have a good supply for Xmas, otherwise they will loose momentum against Sony and MS.

In july, Wii has "only" sold 4 times more than PS3, when in june it was 6 times, in may 5 times, and in april... 4 times... rather than a "decline", i'd call this a very normal situation, with very steady Wii sales, and a just slightly better situation for the PS3...

It's very simple, just look at the vgchartz Japan's hardware sales graphic:

http://www.vgchartz.com/hwcomps.php?cons1=Wii&reg1=Japan&cons2=PS3&reg2=Japan&cons3=X360&reg3=Japan&align=1

You see that blue line? That's the Wii...

Is it falling? Even just a little bit? If you have good eyes, you have a good answer...

All I know is that according to another thread the wii's are much easier to find in japan, and its been dropping for a while, hopefully its not a permenant situation.

WOW! look at this, it describes wii sales in June and July.  Oh wait there's something beating the Wii in japan....

Check this:

http://gonintendo.com/?p=22352

Wii sales nearly doubled in July (in comparison to June).

Considering that MP8 came out in late July, maybe the Wii was almost sold out by then...

Again: This is one report saying the Wii´s are in stock since the 29th. The report came in at 30th. That means they got a new shipment on the 29th and a PS3 fan ran into the store, saw Wii´s and reported nobody was buying Wii anymore

Are you dumb or something? That link you posted is total sales so far, ofcourse its going to be rising since they arent being returned and they are selling, its weekly sales for the past 3-4weeks its been declining in japan, here is the link

http://www.vgchartz.com/hwcomps.php?cons1=Wii&reg1=Japan&cons2=PS3&reg2=Japan&cons3=X360&reg3=Japan&align=1&weekly=1

Yeah declining because "Enterbrain has pulled together some data to come up with what they see as the Wii total sales in Japan for the month of July. According to them, Nintendo managed to move 396,752 units. That nearly doubles the amount Nintendo sold in June. For comparison, Sony sold 91.987 PS3 units for July in Japan."

ONLY! This is not acceptible!! 

This whole notion that Wii sales in Japan are declining is a gigantic pile of baloney. July sales were the highest of any month this year! Kotaku's article just demonstrates how you can give statistics that are 100% accurate, yet convey a completely misleading picture.

For fun, I've continued TalonMan's listing of Japanese Wii sales above. All numbers from the vgchartz weekly listings, rounded to the nearest thousand.

July
7/29 74k
7/22 83k
7/15 110k (Dragon Quest Swords)
7/08 75k
7/01 76k
Average (5 weeks): 83.6k

June
6/24 67k
6/17 69k
6/10 66k
6/03 71k
Average (4 weeks): 68.3k

May
5/27 61k
5/20 56k
5/13 55k
5/06 91k (Golden Week)
Average (4 weeks): 65.8k

April
4/29 91k (Golden Week)
4/22 73k
4/15 71k
4/08 50k
4/01 47k
Average (5 weeks): 66.4k

March
3/25 83k
3/18 67k
3/11 48k
3/04 61k
Average (4 weeks): 64.8k

Conclusion: Wii sales in Japan have largely been stable this year, pushing around 65k per week on average. Some weeks the supply is higher, some weeks it's lower, but the average has been pretty consistent. The month of July is well above normal sales, so any conclusion that the "fad" is dying out would be completely and utterly misplaced.

If you only look at one or two weeks of the chart, you miss what's really going on. Or, let me put it this way: Sony fans can take heart that the Wii only sold 47k and 50k units the first two weeks of April! That must mean that PS3 Domination is about to begin - the fad is OVER! :p