I also think every reservation count above 100k is nuts. My guess is 20k within 24 hours and 80k by the end of the year (that would be X reservations times 4 to 5, roughly speaking).
The Tesla fan base is growing worldwide but Tesla Motors is still unkown to the masses. We need more videos going viral, and perhaps, we also need more fan-made ads in the traditional media (magazines, TV, cinema, etc)
To add, traditional auto-makers (and their mass media friends) will continue to talk Tesla down (at least this is what's happening in Germany) and spread fear and doubt about Tesla's future, with regards to Tesla's balance sheet (losses), production & QC problems and what not. Then again, most media outlets will point to the many delays of the Model X launch and slow ramp up, and question the delivery estimates.
So, I expect lots of feat mongering a la "You pay one grande now and you'd probably get your car in 3-4 years time, and not next year".
This will all have a negative impact on actual reservations. Don't expect crazy numbers here.