First, thankyou thankyou thankyou thankyou thankyou
thankyou very much for Aalto.
Now, I have some ideas/suggestions. 
1) External clock for sequencer.
Two options: clock sequencer with note on from 
another MIDI track or use one note from same MIDI 
track (something like lowest MIDI note or some user 
defined note) to clock sequencer (that pll drift is great but infew occasions I want tight sequence or uneven stepping trough sequence)
2) Add Modulator->Carrier amplitude/ring modulation 
along with FM
3) Variation on Carrier oscillator: shape is mix 
between sine and saw/square. In some situations even 
small amounts of saw and square produce too much HF 
buzz. Now, there is that trick where if you take sine 
osc out and put it in FM input you get saw-alike wave 
(similar if you feedback sqaured output you get 
square-alike wave). It works very good and it's very 
stable in digital domain even with high feedback 
amount if some filtering is applyed in feedback path. 
So idea is to have another mode for carrier: shape 
parameter would increase feedback on one side (and 
feedback of squared output on other) and there would 
be no mixing of wavefolder and waveshaper blocks but 
rather waveshaper (carrier it self in this case) 
would allways feed wavefolder (i guess some 
additional stuff like dropping fback/shape amount at 
high folding amount would be needed at higher 
registers).
4) Separate outputs for Modulator and Carrier for 
modular routing (for stuff like filter FM and 
similar)
5) Add option for bandpass filter in waveguide loop 
instead of peaking filter
6) Add mod input for gate decay
7) Numerical input. In few occasions I want very very 
precise control of some parameter value, so something 
like "right click for popup where you eneter value 
from keyboard" would be nice.
That's it (for now :) ), and I wish happy 2013. to
all.
Thanks for all this feedback! I am considering all of these ideas, even I don't reply point by point. Some of these things are for sure doable and will show up at some point in the future. Please keep in touch.