Just as the title says, nintendo today has updated the 3DS firmware from V4.0.0-7 to V4.1.0-8. Looks like the new firmware didn't change too much, here is the only changelog of it ""System Update (In System Settings) can now be entered without a Parental Control Pin"".
And also it has been confirmed that the new 3DS firmware do not block any flashcart. Nearly all the flashcarts can still work on the new firmware. such as R4i golds 3ds (r4ids.cn), Acekard 2i and DStwo. So feel free to update your 3DS and don't worry it would ban your flashcart.