Also true

Just for the record: you can buy a longer lasting battery, it will just poke out of the back. There are currently no batteries in an affordable price range that will be small enough to fit inside the 3DS; and there won't be for some time.

There's like three models of DS on the market right now, too.  The recently discontinued Lite, the DSi, and the DSi XL.  The 3DS will do well when there's a reason to buy one but for now, the value of the original DS library and the low cost of the system is what's stopping the 3DS. 

One thing I hate to admit:  Smart phone games.  I haven't bought a DS game for myself in a couple of years (despite owning six DS's).  I still buy PSP games but I barely feel like investing my time in full fledged games for the portable.  I've barely played Valkyria Chronicles 2 despite loving VC1 and buying VC2 on day 1.  The bite sized distraction of smart phones may be doing more damage than we think.......

This is most likely a price to value issue for most potential customers.

Currently, for $250, the 3DS doesn't have proportionate value and won't until it starts seeing some legitimately compelling titles that can't be done on the DS whether that's due to the additional processing power, use of 3D effects built into the game design and game play, or other features like Street Pass.

In a slightly worse case scenario, 3DS sales will pick up when Nintendo simply stops making ports of the latest versions of their key IPs for the DS, at which point fans of their games will either skip the games or buy a 3DS.

The pricing issue is always an easy fix however. If production relative to demand is strained, either you sell your product for more or, pass that additional profit to secondary sales (Ebay/hardware flippers) as was the case with the Wii. Nintendo can always drop price once production exceeds demand given the low unit cost of the 3DS.

Given the relatively low difference in production cost between the DS and the 3DS, it does seem a bit less likely that Nintendo will keep the DS in production throughout the entire life cycle of the 3DS for anything other than as a low-cost (to consumers) alternative to maintain a broader market for their games.

and there are solar-akkus where you can load your device like 3 times and only costs like 30bucks.

Im definately going to buy a solar-akku once I get a NGP, so Battery should defenately not be a problem, if its over 3h of curse

Just you wait till Mario Kart hits.

this. and pokemon oh go-

Indeed. Once Pokemon's out, it'll be a done deal.

Don't let those petty games distract you.  I just got two good used DS games on Amazon for barely over 30 dollars including shipping.  I for some reason didn't buy a Professor Layton game which I have yet to try but heard great things about them.  I am also interested in the Ace Attorney games.  Once the 3DS takes off even more I am sure you can find tons of DS gems for dirt cheap on Amazon.

I, for one, would definitely not purchase a 3DS if it was not backwards compatible