The Consensus page is just marketing, only code speaks the truth. The promise was to open it as soon as possible, but the more time passes in silence the more we can reason it to be either a lie, or impossible due to security constraints resulting from a proprietary and rushed development process. It's getting tiresome to repeat this and hearing no arguments but "look, consensus!". If you believe in reading web pages, read that one for a different perspective:
http://ripplescam.org/.
Where on ripplescam does it give proof that the consensus mechanism does NOT work (or can not work)?
Just saying "it's not Open Source, so it cannot be true" is a position that I cannot really identify with - existance of an implementation does not guarantee or imply correct workings. Also you're free to implement a consensus mechanism as outlined in the Wiki and use this to either prove or disprove the feasability of dispute resolution using consensus.
I am not sure what you mean by natively integrating BTC into ripple. For one there are already gateways which do this via ripple IOUs. If you think there'll be native bitcoin proof of ownership in ripple, dream on. Second, for open sourcing the server code, I wouldn't bet on it.
IOUs are inherently different from currencies like (native) BTC or XRP. IOUs have a certain value (0%-100% of the thing that is owed) but get destroyed once you actually redeem them. They exist to be destroyed. Currencies have 0 redeemable value (yes, both BTC and XRP), but have utility in being used for price discovery and have the big advantage that they can be actually owned as an asset, since they won't (and cannot) be redeemable with anyone for anything. The actual price of a currency comes from it's utility and even more the trust that people have in it.
If you use now BTC IOUs (e.g. MtGox BTC codes) as "currency" in Ripple or elsewhere, you again need to trust a person to redeem them and not a currency to be useful. It wouldn't matter if you used USD IOUs, XAU IOUs, BTC IOUs or LTC IOUs - what you are using is always IOUs that have different features than an actual currency.
As for a mesh exchange, again this is not something new, ripple users can elect to exchange whatever IOUs they have directly instead of via a centrally controlled reserve currency. There is no need for a privileged reserve currency to facilitate exchanges. Users are likely to adopt bitcoin or USD or something else for this purpose voluntarily, something they can trust. But at the moment they cannot trust the ripple network, XRP or not.
Actually I disagree with you on this - if there is no generally accepted currency (it does not need to have a reserve, it just needs to be trusted by people and be useful as a currency), there will be one created implicitly. The big danger imho is that if there is no native currency (something that you can own) this will be the most dispersed or otherwise highly trusted IOU. Bitcoin trading already suffers from high centralization towards MtGox, now imagine you cannot trade Bitcoins any more but only coins deposited at MtGox. Once you take away a central 0-value currency, another central currency would emerge. If that turns out to be an IOU, bad things can and will happen.
The point of this thread now is on how BTC can be used as this central currency (meaning I can exchange Ripple IOUs or native BTC for Ripple IOUs within Ripple instead of Ripple IOUs and XRP for Ripple IOUs) or at least be used next to XRP. There is already a thread at the Ripple forums about this, JoelKatz' stance seems to be that BTC would not be useful as they have a different target group, are slow and would be taken over by XRP because of this as XRP are inherently more useful than BTC in a Ripple system. If you disagree with this, I'd like to hear your reasons and ideas and please not again some rants about how the code should be open sourced yesterday. Please get more concrete - instead of "clearly this can be tuned" say "Sha512 hashing with a difficutly of 0.01 just takes X cycles on a modern CPU, so this costs just 0.000x USD assuming a power usage of 50W and Y cycles per second."
Lastly, I'm really fed up with the "shilling" accusations. I try my best to be constructive here, it is not very easy sometimes though. It would be great to have some useful discussions as this would also help the OT+BM implementation probably, which seems to me to be something similar to this "mesh exchange". I'm not too sure how one can trade there though (with trading meaning something different than investing) and what the implications of that would be.